Publications by authors named "Jamshidkhan Chamani"

50 Publications

Folate targeted PEGylated liposomes for the oral delivery of insulin: In vitro and in vivo studies.

Colloids Surf B Biointerfaces 2020 Oct 17;194:111203. Epub 2020 Jun 17.

Biotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, 91775-1365, Iran; Nanotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran; Department of Pharmaceutical Nanotechnology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, 91775-1365, Iran. Electronic address:

In this study using phospholipids with high transition temperature and taking advantage of PEGylation, we designed liposomal formulation targeted with folic acid (FA) to improve the stability of liposomes with high penetration efficiency at the same time. The results of characterization demonstrated that liposomal formulations are in range of 150-210 nm size with negative surface charge. The results of cell uptake indicated that FA conjugation resulted in the more uptake of insulin. However, the results of transepithelial electrical resistance (TEER) showed no statistical differences among the formulations. The results of biodistribution also demonstrated that PEGylated liposome targeted with FA had more residence time in stomach and intestine along with higher amounts in blood and liver. The anti-diabetic effects of formulation in vivo indicated the efficacy of PEGylated liposome targeted with FA had promising results in decreasing blood glucose and increasing insulin levels. The results of this study indicated that using phospholipids with high Tm along with PEGylation and using targeting ligand could improve efficiency of oral delivery of liposomes which merit further investigation.
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http://dx.doi.org/10.1016/j.colsurfb.2020.111203DOI Listing
October 2020

Analysis of the interaction behavior between Nano-Curcumin and two human serum proteins: combining spectroscopy and molecular stimulation to understand protein-protein interaction.

J Biomol Struct Dyn 2021 Jun 20;39(9):3358-3377. Epub 2020 May 20.

Department of Biology, Faculty of Sciences, Mashhad Branch, Islamic Azad University, Mashhad, Iran.

In this study, we have investigated the effects of Nano-curcumin (Nano-CUR) binding on HSA-HTF interactions as binary and ternary systems, which had been done through multiple spectroscopic and MD simulation. It has been indicated by fluorescence spectroscopy that Nano-CUR is capable of quenching both proteins with a static mechanism. Thermodynamic parameters have been calculated by considering the fluorescence data at different temperatures. The binding constants of HSA-Nano-CUR, HTF-Nano-CUR and (HSA-HTF) Nano-CUR complexes formation were (2.03 ± 0.32)×10 (2.46 ± 0.32)×10 and (4.54 ± 0.32)×10 respectively. According to the negative values of ΔH and ΔS, the roles of van-der-Waals forces and hydrogen bond are quite essential throughout this particular binding. Besides, the negative ΔH and ΔS values of HTF (Nano-CUR) have been larger than those of the HSA (Nano-CUR) and HSA-HTF (Nano-CUR), which demonstrates the higher significance of interaction bonding. As it had been detected through the synchronized fluorescence spectroscopy at Δλ = 60 nm, the position of Nano-CUR with mixed protein in ternary system has been closer to Tyr residues. Relatively, the binding distances between Trp residues of HSA and HTF in HSA (Nano-CUR), HTF (Nano-CUR), and (HSA-HTF Nano-CUR) complexes, which had been procured in accordance with the fluorescence resonance energy transfer (FRET), have been found to be 1.82 nm, 1.87 nm, and 1.92 nm, respectively. We have evaluated the induced conformational changes of two proteins throughout the binding of Nano-CUR to HSA and HTF as binary and ternary systems by employing the CD technique, while the formation of self-assemblies has been studied through MD simulation.
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http://dx.doi.org/10.1080/07391102.2020.1766570DOI Listing
June 2021

Characterizing the Binding of Angiotensin Converting Enzyme I Inhibitory Peptide to Human Hemoglobin: Influence of Electromagnetic Fields.

Protein Pept Lett 2020 ;27(10):1007-1021

Department of Biology, Faculty of Sciences, Mashhad Branch, Islamic Azad University, Mashhad, Iran.

Background: Drug-protein complexes is one of the crucial factors when analyzing the pharmacokinetics and pharmacodynamics of a drug because they can affect the excretion, distribution, metabolism and interaction with target tissues.

Objectives: The aim of this study was to investigate the interaction of human hemoglobin (Hb) and angiotensin I converting enzyme inhibitory peptide (ACEIP) in the absence and presence of different- frequency electromagnetic fields (EMF).

Methods: Various spectroscopic methods like fluorescence spectroscopy, ultraviolet, circular dichroism and conductometry techniques were applied to investigate Hb-ACEIP interaction in the absence and presence of EMF.

Result: The presented spectroscopic studies indicated that EMF changed the interaction between Hb and ACEIP. The a-helix content of Hb decreased upon binding to ACEIP and conductivity of the solution enhanced upon binding. Based on Stern-Volmer equations, it could be stated that the Hb-ACEIP affinity was higher in the presence of EMF.

Conclusion: It can be concluded that for patients who use the drug to control blood pressure, a low-frequency electromagnetic field would have a positive effect on the uptake of the drug.
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http://dx.doi.org/10.2174/1871530320666200425203636DOI Listing
January 2021

Oil-in-water nanoemulsions comprising Berberine in olive oil: biological activities, binding mechanisms to human serum albumin or holo-transferrin and QMMD simulations.

J Biomol Struct Dyn 2021 Feb 12;39(3):1029-1043. Epub 2020 Feb 12.

Department of Biology, Faculty of Sciences, Mashhad Branch, Islamic Azad University, Mashhad, Iran.

Berberine is widely used in traditional Iranian medicine to treat diabetes and inflammatory conditions. This study was aimed at developing a method for the preparation of Berberine nanoparticles (Nano-Ber) in order to improve its aqueous-phase solubility and its complex formation with human serum albumin (HSA) and holo-transferrin (HTF) from the viewpoint of interaction behavior. Nano-Ber was prepared with olive oil as the oil phase, Tween 80 as the surfactant and Span 60 as the co-surfactant. Nano-Ber was obtained with a spherical shape and a mean particle size of 43.7 ± 3.6 nm, with an optimal oil:surfactant:co-surfactant ratio of 1:2:2, w/w/w. The antioxidant activity of Nano-Ber in comparison with Berberine was tested using DPPH and it was found that Nano-Ber had a large antioxidant activity. The cytotoxicity effects of Nano-Ber and Berberine on HepG2 were compared by MTT assay and detected in the treated HepG2 cells at concentrations up to 0.1 mM. The binding constants of HSA-Nano-Ber and HTF-Nano-Ber complexes formation were (2.93 ± 0.02) × 10 and (9.62 ± 0.03) × 10, respectively. Hydrogen bonds and van der Waals interactions were the predominant forces in the HSA-Nano-Ber and HTF-Nano-Ber complexes, and the process of Nano-Ber binding HSA and HTF was driven by Δ = -122.76 kJ mol, Δ = -325.49 J molK for HSA and Δ = -125.09 kJ mol, Δ = -43.37 J molK for HTF. The results of the simulation demonstrated that the Nano-Ber molecules were stabilized on the surface of final aggregates through both hydrophilic and hydrophobic interactions. Communicated by Ramaswamy Sarma.
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http://dx.doi.org/10.1080/07391102.2020.1724568DOI Listing
February 2021

The effect of nanomicelle curcumin, sorafenib, and combination of the two on the cyclin D1 gene expression of the hepatocellular carcinoma cell line (HUH7).

Iran J Basic Med Sci 2019 Oct;22(10):1198-1202

Vascular and Endovascular Surgery Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.

Objectives: Hepatocellular carcinoma (HCC) is one of the most significant health condition around the world. As the only curative therapies, liver transplantation and surgical resection are the clinical treatments of HCC. Due to the systemic toxicity and severe side effects of these treatments, it is vital to establish new therapeutic approaches. The present study aimed to compare cyclin D1 (CCN D1) gene expression in hepatocellular carcinoma cell line (HUH7) when it is treated with nanomicelle curcumin and sorafenib. The purpose was to identify toxicity risk and antioxidant activity of these drugs.

Materials And Methods: The toxic dose (IC) of nanomicelle curcumin and sorafenib were detected after treatment of HUH7 cell lines with different dose of mentioned agents followed by MTT assay. CCN D1 gene expression was evaluated using real-time PCR. Following the Tukey's multiple comparison tests, statistical analysis is done through Student's t-test or ANOVA.

Results: The expression of the CCN D1 gene was statistically significant (<0.001) at 289.31, 128 and 152.36 for sorafenib, nanomicelle curcumin and SNC (sorafenib-nanomicelle curcumin) respectively. The finding of this study revealed that, in comparison to sorafenib alone, the treatment of HUH7 with a nanomicelle curcumin IC dose, in combination with sorafenib, might down-regulate CCN D1 gene expression.

Conclusion: The present research indicates that the treatment of the cell line with only nanomicelle curcumin results in the down-regulation of cyclin D1. To further decrease cyclin D1 expression, the co-delivery of curcumin and sorafenib appears to induce the apoptotic process. As a result, the effect of sorafenib cytotoxicity and CCN D1 gene expression decreases twofold.
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http://dx.doi.org/10.22038/ijbms.2019.35808.8530DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6885396PMC
October 2019

A novel view of the separate and simultaneous binding effects of docetaxel and anastrozole with calf thymus DNA: Experimental and in silico approaches.

Spectrochim Acta A Mol Biomol Spectrosc 2020 Mar 30;228:117528. Epub 2019 Oct 30.

Department of Biology, Faculty of Sciences, Mashhad Branch, Islamic Azad University, Mashhad, Iran. Electronic address:

DNA stands as the primary purpose of many anticancer drugs and according to the performed research on this field, some certain changes contain crucial functionalities in the regulated transcription of DNA. Therefore, the interaction between anticancer drugs and DNA play an important role in understanding their function and also provide a better groundwork for producing more efficient and newer drugs. Here, the interaction between Docetaxel (DO) and calf thymus DNA (ct DNA), in the presence and absence of Anastrozole (AN), has been examined through the usage of different methods that include isothermal titration calorimetry, multi-spectroscopic, viscometry, and molecular docking techniques. Interaction studies have been performed by preparing different molar ratios of DO with the constant ct DNA and AN concentration at pH = 6.8. The binding constants have been calculated to be 7.93 × 10 M and 6.27 × 10 M, which indicate the strong binding of DO with ct DNA double helix in the absence and presence of AN, respectively. Thermodynamic parameters, which were obtained from fluorescence spectroscopy and isothermal titration calorimetry, have suggested that the binding of DO and AN to ct DNA as binary and ternary systems have been mainly driven by the electrostatic interactions. The relative viscosity of ct DNA has increased upon the addition of DO and AN, which confirms the interaction mode. A competitive binding study has reported that the enhanced emission intensity of ethidium bromide (EB) and acridine orange (AO), in the presence of ct DNA, have been quenched through the addition of DO and Anastrozole as binary and ternary systems. As it is indicated by these findings, DO is capable of displacing EB and AO from their binding site in ct DNA; hence, it can be concluded that DO and AN are able to intercalate into the base pairs of ct DNA in binary and ternary systems. Molecular docking studies have corroborated the mentioned experimental results.
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http://dx.doi.org/10.1016/j.saa.2019.117528DOI Listing
March 2020

Preparation, in vitro and in vivo evaluation of PLGA/Chitosan based nano-complex as a novel insulin delivery formulation.

Int J Pharm 2019 Dec 17;572:118710. Epub 2019 Oct 17.

Department of Biology, Faculty of Sciences, Mashhad Branch, Islamic Azad University, Mashhad, Iran.

The smart self-regulated drug delivery systems for insulin administration are desirable to achieve glycemic control, and decrease the long-term micro- and macro vascular complications. In this study, we developed an injectable nano-complex formulation for closed-loop insulin delivery after subcutaneous administration and release of insulin in response to increased blood glucose levels. The nano-complex was prepared by mixing oppositely charged chitosan and PLGA nanoparticles. PLGA nanoparticles were prepared using double-emulsion solvent diffusion method, and were loaded with glucose oxidase (GOx) and catalase (CAT) enzymes. These negatively charged particles decrease micro-environmental pH, by gluconic acid production in the glucose molecules presence. Positively charged chitosan nanoparticles were prepared using ionic gelation method, and were loaded with insulin. These nanoparticles (NPs) released insulin by dissociation in acidic pH caused by the GOx activity. Following in vitro studies, in vivo evaluation of nano-complex formulations in streptozocin induced diabetic rats showed significant glycemic regulation up to 98 h after subcutaneous administration.
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http://dx.doi.org/10.1016/j.ijpharm.2019.118710DOI Listing
December 2019

The immunotoxin activity of exotoxin A is sensitive to domain modifications.

Int J Biol Macromol 2019 Aug 23;134:1120-1131. Epub 2019 May 23.

Department of Medicinal Chemistry, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran; Bioinformatics Research Center, Mashhad University of Medical Sciences, Mashhad, Iran. Electronic address:

Immunotoxins are a class of recombinant proteins which consist of an antibody and a part of a bacterial or herbal toxin. Immunotoxins containing Pseudomonas aeruginosa exotoxin A (PEA) have been found to be very applicable in clinical trials. Many obstacles such as solubility and absorbency reduce their usability in solid tumors. The current study aims to overcome the mentioned barriers by addition and removal of functional and non-functional domains with a structural approach. In the experimental section, we took advantage of molecular dynamics simulations to predict the functionality of candidate immunotoxins which target human HER2 receptors and confirmed our findings with in vitro experiments. We found out when no changes were made to domain II of PEA, addition of solubilizing domains to immunotoxins would not reduce their targeting and anti-tumor activity, while increasing the yield of expression and stability. On the other side, when we replaced domain II with eleven amino acids of furin cleavage site (FCS), the activity of the immunotoxin was mainly affected by the FCS neighboring domains and linkers. A combination of seven beneficial point mutations in domain III was also assessed and reconfirmed that the toxicity of the immunotoxin would be reduced dramatically. The obtained results indicate that the addition or removal of domains cannot depict the activity of immunotoxins and the matter should be assessed structurally in advance.
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http://dx.doi.org/10.1016/j.ijbiomac.2019.05.137DOI Listing
August 2019

Nano-curcumin's suppression of breast cancer cells (MCF7) through the inhibition of cyclinD1 expression.

Breast Cancer (Dove Med Press) 2019 13;11:137-142. Epub 2019 Mar 13.

Neurogenic Inflammation Research Center, Mashhad University of Medical Sciences, Mashhad, Iran,

Background: Breast cancer is the leading cause of cancer worldwide. The high expenses associated with chemotherapy as well as its side effects make the management of breast cancer a daunting challenge. The most common overexpressed gene in breast cancer is cyclinD1, which induces cell proliferation. Recent investigations into cancer treatment have revealed that curcumin demonstrates potential anti-cancer properties through different pathways. However, the oral bioavailability of curcumin is negligible due to its high hydrophobic structure. Nanotechnology has been employed to overcome this barrier. Nano-formulated curcumin (SinaCurcumin) has been shown to provide a significantly higher bioavailability for oral consumption. However, the efficacy of this nano-formulated drug in breast cancer has not yet been determined. In relation to the breast cancer cell line, the present study compared nano-curcumin's anti-cancer properties with those of cyclophosphamide, adriamycin, and 5-fluorouracil (CAF).

Methods: After treating MCF7 with nano-curcumin and CAF, the present work assessed cell viability via an MTT assay. The effects of these drugs on cyclinD1 expression were measured by real-time PCR. SPSS 16.0 was used to perform ANOVA and multiple range tests.

Results: Nano-curcumin and the CAF regimen both lowered the viability of MCF7. Nano-curcumin decreased cell proliferation by 83.6%, which was more than that achieved by cyclophosphamide (63.31%), adriamycin (70.75%), and 5-fluorouracil (75.04%). In addition, curcumin was able to significantly reduce the expression of cyclinD1, whereas CAF did not alter cyclinD1 expression.

Conclusion: Nano-curcumin has a relatively high cytotoxic effect on MCF7 breast cancer cells, suppressing the expression of cyclinD1, a critical gene in the development and metastasis of breast cancer. The current study demonstrated that nano-curcumin can be an effective drug in the CAF regimen for the treatment of breast cancer. However, further in vivo research is needed for determining its efficacy and safety in clinical applications.
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http://dx.doi.org/10.2147/BCTT.S195800DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6420787PMC
March 2019

Determining the interaction behavior of calf thymus DNA with berberine hydrochloride in the presence of linker histone: a biophysical study.

J Biomol Struct Dyn 2020 02 17;38(2):364-381. Epub 2019 Feb 17.

Department of Biology, Faculty of Sciences, Mashhad Branch, Islamic Azad University, Mashhad, Iran.

The binding of small molecules with histone-DNA complexes can cause an interference in vital cellular processes such as cell division and the growth of cancerous cells that results in apoptosis. It is significant to study the interaction of small molecules with histone-DNA complex for the purpose of better understanding their mechanism of action, as well as designing novel and more effective drug compounds. The fluorescence quenching of ct-DNA upon interaction with Berberine has determined the binding of Berberine to ct-DNA with  = 9.46 × 10 M. value of ct-DNA-Berberine in the presence of H1 has been observed to be 3.10 × 10 M, indicating that the H1 has caused a reduction in the binding affinity of Berberine to ct-DNA. In the competitive emission spectrum, ethidium bromide (EB) and acridine orange (AO) have been examined as intercalators through the addition of Berberine to ct-DNA complexes, which includes ctDNA-EB and ctDNA-AO. Although in the presence of histone H1 , we have observed signs of competition through the induced changes within the emission spectra, yet there has been apparently no competition between the ligands and probes. The viscosity results have confirmed the different behaviors of interaction between ctDNA and Berberine throughout the binary and ternary systems. We have figured out the IC50 and viability percent values at three different time durations of interaction between Berberine and MCF7 cell line. The molecular experiments have been completed by achieving the results of MTT assay, which have been confirmed to be in good agreement with molecular modeling studies.Communicated by Ramaswamy H. Sarma.
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http://dx.doi.org/10.1080/07391102.2019.1574240DOI Listing
February 2020

Synergistic effects of and radiotherapy on induction of cytotoxicity in HeLa cell line.

Avicenna J Phytomed 2018 Sep-Oct;8(5):439-477

Cancer Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.

Objective: Cervical cancer is the second most common type of cancer among women, worldwide; and for treatment of this type of cancer radiotherapy is commonly used. Boiss ("Barije" in Persian, from the family Apiaceae), (F. gummosa), is an extremely precious medicinal plant which naturally grows throughout the Mediterranean and Central Asia and is a native plant in Iran. The present study examined the cytotoxic effects of in terms of induction of apoptosis and radiosensitivity in HeLa cells.

Materials And Methods: In order to determine cytotoxicity in HeLa cells, the cells were incubated with different concentrations of the plant resin (0-1000 µg/ml) for 24, 48 and 72 hr. Cytotoxicity was determined by MTT assay. The role of apoptosis in cytotoxicity was investigated using flow cytometry following propidium iodide (PI) staining of DNA. For radiosensitivity assessment, -treated cells were exposed to 2 Gy γ-rays, and cytotoxicity was determined in irradiated and non-irradiated (control) groups by MTT and the synergism factor was calculated.

Results: decreased cell viability in HeLa cells in a concentration- and time-dependent manner. Flow cytometry analysis indicated that apoptosis is involved in -induced cytotoxicity. Co-administration of and radiotherapy showed that this plant at non-toxic low doses, could result in almost 5-fold increment in sensitization of cells towards radiation-induced toxicity.

Conclusion: The concurrent use of and radiation increases radiosensitivity and cell death. Therefore, can be considered as a potential radiosensitizer agent against cervical cancer.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6190245PMC
October 2018

Isothermal titration calorimetry and stopped flow circular dichroism investigations of the interaction between lomefloxacin and human serum albumin in the presence of amino acids.

J Biomol Struct Dyn 2019 Jun 26;37(9):2265-2282. Epub 2018 Nov 26.

a Department of Biology, Faculty of Sciences , Mashhad Branch, Islamic Azad University , Mashhad , Iran.

The present study was designed to investigate the influence of two indispensable and two dispensable amino acids, including methionine, histidine, cysteine and proline, on the binding interaction between human serum albumin (HSA) and an antibiotic agent lomefloxacin (LMF). The fluorescence quenching experiments showed that the intrinsic emission of HSA was considerably quenched following binding to LMF in all the systems. Furthermore, in all the interactions the maximum wavelength of HSA was slightly decreased. The spectral changes observed in the binding systems we e all attributed to the alteration of the micro-environment around the tryptophan and tyrosine residues of HSA. The K values o HSA-LMF complex in the absence and presence of histidine, methionine, cysteine and proline have been obtained 6.02 × 10, 4.83 × 10, 5.05 × 10, 4.94 × 10 and 6.20 × 10 M respectively. The various kind of Kb values showed the different interaction behavior between HSA and LMF in the absence and presence of amino acids mentioned. The data gathered by isothermal titration calorimetry (ITC) studies revealed that although all the binding interactions were exothermic, the amount of the heat exchanged during the HSA-LMF interaction increased in the presence of the amino acids especially cysteine. In the present study, the binding kinetics and affinity of LMF to HSA in the absence and presence of the amino acids were studies using stopped-flow circular dichroism and ITC techniques respectively. The results of these two techniques revealed that the bindig affinity and binding rate of the LMF-HSA interaction decreased in the presence of histidine, methionine and cysteine. In the presence of proline, the binding process of LMF-HSA was sped up and the affinity of LMF to HSA slightly increased. All the experimental results were then supported by the data collected from molecular modeling studies using density functional theory. Communicated by Ramaswamy H. Sarma.
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http://dx.doi.org/10.1080/07391102.2018.1491421DOI Listing
June 2019

An Study on Curcumin Delivery by Nano-Micelles for Esophageal Squamous Cell Carcinoma (KYSE-30).

Rep Biochem Mol Biol 2018 Apr;6(2):137-143

School of Medicine, University of Birmingham, Birmingham, UK.

Background: The incidence of esophageal squamous cell carcinoma (ESCC) is increasing, causing catastrophic health burdens on communities. Curcumin has shown promise as a therapeutic agent in the treatment of colon, colorectal, pancreatic, and esophageal cancers but it has very poor bioavailability. The application of nano-carriers as drug delivery systems increases curcumin's bioavailability. Cyclin D1 is overexpressed in ESCC and curcumin may change its expression.

Methods: In this study, the effect of SinaCurcumin®, a novel nano-micelle product containing 80 mg curcumin, on the growth of KYSE-30 cells and expression of cyclin D1, was investigated. Paclitaxel and Carboplatin served as reference drugs.

Results: Nano-curcumin increased cell cytotoxicity, decreased IC, and down-regulated of cyclin D1. However, treatment of cells with nano-curcumin might result in multidrug resistance.

Conclusion: Nano-curcumin suppressed proliferation of KYSE-30 cells and expression of cyclin D1 although its use in combination with other chemotherapeutic agents requires further testing.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5941128PMC
April 2018

Use of spectroscopic and zeta potential techniques to study the interaction between lysozyme and curcumin in the presence of silver nanoparticles at different sizes.

J Biomol Struct Dyn 2019 May 24;37(8):2030-2040. Epub 2018 Nov 24.

a Department of Biology, Faculty of Sciences , Mashhad Branch, Islamic Azad University , Mashhad , Iran.

This article describes, for the first time, the effect of three different sizes of silver nanoparticles on the binding of curcumin to lysozyme as examined by spectroscopic and zeta potential techniques at physiological conditions. The binding constants of curcumin to lysozyme in the presence of silver nanoparticles were measured. Based on the results of synchronous fluorescence and three-dimensional fluorescence spectroscopy, the presence of the different sizes of silver nanoparticles caused conformational changes in lysozyme during the binding of curcumin. Such changes were also observed when increasing the curcumin concentration. The results of fluorescence resonance energy transfer theory indicated that different sizes of silver nanoparticles could change the binding distance between curcumin and lysozyme. Based on the red edge excitation shift approach, we concluded that the limited mobility around the Trp residues decreased in the presence of silver nanoparticles with bigger size. Under resonance light scattering, the aggregation of curcumin on lysozyme in the presence of silver nanoparticles can play a major role in functional proteins. Communicated by Ramaswamy H. Sarma.
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http://dx.doi.org/10.1080/07391102.2018.1475258DOI Listing
May 2019

Multi-spectroscopic and molecular modeling studies to reveal the interaction between propyl acridone and calf thymus DNA in the presence of histone H1: binary and ternary approaches.

J Biomol Struct Dyn 2019 Feb 6;37(2):359-371. Epub 2018 Feb 6.

a Faculty of Sciences, Department of Biology , Islamic Azad University, Mashhad Branch , Mashhad , Iran.

DNA is the primary target of many anticancer drugs involved in important intercellular processes, especially in transcriptional regulation, and histone is known to inhibit gene expression. Small molecules can bind to histone-DNA and impair the cell division, growth, inhibition, and apoptosis in cancer cells. In this research, the interaction of a histone H1-calf thymus DNA (ct DNA) complex and propyl acridone (PA) was investigated in Tris-HCl buffer, pH 6.8, using multi-spectroscopic, viscosity, and molecular modeling techniques. The Stern Volmer plot of the (H1-ct DNA) PA complex demonstrated two sets of binding sites with various binding affinities at three different temperatures. Thermodynamic parameters (ΔH° < 0 and ΔS° < 0) indicated that hydrogen bonds and van der Waals forces played the main roles in the binding of the drug to H1-ct DNA. The interaction between PA and ct DNA as well as (H1-ct-DNA) in the presence of acridine orange and ethidium bromide showed two different interaction behaviors in ternary systems. According to results from UV absorption spectroscopy and melting temperature (Tm) measurements, the binding mode of PA with ct DNA and the (H1-ct DNA) complex was indicative of an intercalative binding for the binary system and of both intercalative with groove binding with molecular fraction for the ternary system. Furthermore, the PA-induced detectable changes in the circular dichroism spectrum of ct DNA as well as changes in its viscosity. All of the experimental results proved that the intercalative binding between PA and ct DNA as well as the (H1-ct DNA) complex as binary and ternary systems must be predominant. The results obtained from experimental data were in good agreement with molecular modeling with regard to the determination of the binding site of PA to ct DNA in the absence and presence of histone H1.
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http://dx.doi.org/10.1080/07391102.2018.1427629DOI Listing
February 2019

Improving efficiency of an angiotensin converting enzyme inhibitory peptide as multifunctional peptides.

J Biomol Struct Dyn 2018 Nov 7;36(14):3803-3818. Epub 2017 Dec 7.

d Department of Immunology, School of Medicine , Hamadan University of Medical Sciences , Hamadan , Iran.

Bioactive peptides have been defined as specific protein fragments that have numerous biological activities. The aim of this study was to introduce three multifunctional peptides. Hence, we used rabbit lung angiotensin converting enzyme (ACE) inhibitor peptide AFKDEDTEEVPFR to prepare two analogous peptides KDEDTEEVP and KDEDTEEVH. ACE inhibitory, antioxidant, and antimicrobial activities of three synthetic peptides were investigated. Among the three peptides, KDEDTEEVP exhibited the highest ACE inhibitory activity with IC value of 69.63 ± 2.51 μM. Furthermore, the results of fluorescence spectroscopy and molecular modeling showed that KDEDTEEVP had more affinity to ACE than other peptides. The peptide of KDEDTEEVH showed the strongest antioxidant scavenging capacity on DPPH radicals (EC = 135 ± 9.62 μM), hydroxyl radicals (EC = 144 ± 8.73 μM), and ABTS radicals (EC = 62 ± 4.52%). Moreover, it showed the highest activity in iron-chelating test (EC = 226 ± 14.13 μM) and could also effectively inhibit the peroxidation of linoleic acid. The antimicrobial activity results showed that KDEDTEEVH had higher efficiency against Gram-positive than Gram-negative bacteria with MIC values of higher than 205 ± 10.75 μM. Although there was not a direct correlation between ACE inhibitor and antioxidant activity for analogous peptides, both analogous peptides exhibited more efficiency than the mother peptide. Thus, they can be considered as multifunctional peptides and would be beneficial ingredient to be used in food and drug industry.
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http://dx.doi.org/10.1080/07391102.2017.1401001DOI Listing
November 2018

Determining the binding site and binding affinity of estradiol to human serum albumin and holo-transferrin: fluorescence spectroscopic, isothermal titration calorimetry and molecular modeling approaches.

J Biomol Struct Dyn 2018 May 2;36(7):1747-1763. Epub 2017 Jun 2.

a Department of Biochemistry and Biophysics, Faculty of Sciences , Mashhad Branch, Islamic Azad University , Mashhad , Iran.

The interactions between estradiol and two carrier proteins, i.e. human serum albumin (HSA) and holo-transferrin (HTF) in aqueous solution at pH = 7.4 were studied by three-dimensional fluorescence emission spectroscopy, isothermal titration calorimetry (ITC), zeta-potential, resonance light-scattering and molecular modeling. Extensive fluorescence quenching was observed throughout the interaction between the drug and both proteins. Moreover, conformational changes were determined by observing the rearrangement of Trp residues during binding of estradiol with HSA and HTF at different concentrations. ITC experiments revealed that, in the presence of estradiol, both van der Waals forces and hydrogen bonding became predominant. In addition, other binding parameters such as enthalpy and entropy changes were determined by the zeta potential method. Molecular modeling suggested that estradiol was situated within sub-domain IB sited in the hydrophobic cluster in Site I, whereas the drug was located in the N-terminal of HTF where it was hydrogen bonded with Ala 670.
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http://dx.doi.org/10.1080/07391102.2017.1333460DOI Listing
May 2018

Enhanced sublingual immunotherapy by TAT-fused recombinant allergen in a murine rhinitis model.

Int Immunopharmacol 2017 Jul 11;48:118-125. Epub 2017 May 11.

Immunobiochemistry Lab, Immunology Research Center, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran. Electronic address:

Allergen-specific sublingual immunotherapy (SLIT) is well known as an effective and non-invasive route to induce allergy desensitization. The goal of this study was to investigate whether a TAT-fused recombinant allergen could enhance SLIT efficacy. BALB/c mice sensitized to the main allergen (Che a 3) of Chenopodium album pollen were treated sublingually either with rChe a 3 (100μg/dose) or rTAT-Che a 3 (100μg/dose), two times per week for eight weeks. SLIT with rTAT-Che a 3 led to significantly greater allergen-specific IgG2a than rChe a 3; however, neither rTAT-Che a 3 nor rChe a 3 affected allergen-specific IgE or IgG1 antibody levels. In addition, interleukin 4 (IL-4) levels in re-stimulated splenocytes from the rTAT-Che a 3 mice were significantly lower than in those from the rChe a 3 mice, while interferon-γ (IFN-γ) was significantly greater in the rChe a 3 mice than in the rTAT-Che a 3 mice. Furthermore, sublingual administration of rTAT-Che a 3 induced significantly greater TGF-β secretion in re-stimulated splenocytes than administration of rChe a 3. Accordingly, SLIT with rTAT-Che a 3 led to significantly greater expression of TGF-β- and Foxp3-specific mRNAs in the splenocytes than in those from the rChe a 3 mice. Our findings demonstrate that TAT-fused rChe a 3 suppressed the allergic response through preferential enhancement of systemic regulatory T-cell (Treg)-mediated immunity responses, likely by facilitating allergen capture and presentation by sublingual Langerhans-like dendritic cells.
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http://dx.doi.org/10.1016/j.intimp.2017.04.011DOI Listing
July 2017

Biological and Clinicopathological Significance of Cripto-1 Expression in the Progression of Human ESCC.

Rep Biochem Mol Biol 2017 Apr;5(2):83-90

Immunology Research Center, BuAli Research Institute, Mashhad University of Medical Sciences, Mashhad, Iran.

Background: Human Cripto-1, a member of the EGF-CFC family, is involved in embryonic development, embryonic stem cell maintenance, and tumor progression. It also participates in multiple cell signaling pathways including Wnt, Notch, and TGF-β. Remarkably, it is expressed in cancer stem cell (CSC) compartments, boosting tumor cell migration, invasion, and angiogenesis. Although Cripto-1 is overexpressed in a variety of human malignant tumors, its expression in esophageal squamous cell carcinoma (ESCC) remains unclear. Our aim in this study was to evaluate the possible oncogenic role of Cripto-1 in ESCC progression and elucidate its association with clinicopathological parameters in patients.

Methods: In this study, Cripto-1 expression in 50 ESCC tissue samples was analyzed and compared to corresponding margin-normal esophageal tissues using quantitative real-time PCR.

Results: Cripto-1 was overexpressed in nearly 40% of ESCC samples compared with normal tissue samples. Significant correlations were observed between Cripto-1 expression and tumor differentiation grade, progression stage, and location (p < 0.05).

Conclusions: Our results indicate that overexpression of Cripto-1 is involved in the development of ESCC. Further assessment will be necessary to determine the role of Cripto-1 cross talk in ESCC tumorigenesis.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5346274PMC
April 2017

Expression analysis of matrix metalloproteinase-13 in human gastric cancer in the presence of Helicobacter Pylori infection.

Cancer Biomark 2017 ;18(4):349-356

Department of Laboratory Sciences, School of Paramedical Sciences, Mashhad University of Medical Sciences, Mashhad, Iran.

Background: Matrix metalloproteinases (MMPs) can degrade essentially the extracellular matrix (ECM) components. MMPs are important regulators of tumor growth; hence the enzymes are considered as important targets for cancer therapy. MMP-13 is specially activated in gastric cancer and promotes the invasiveness of the primary tumors. Helicobacter Pylori (H.pylori) interacts with gastric epithelial cells and stimulates it to produce MMP-13in vitro.

Objective: The relation between MMP-13 gene expression and clinicopathological characteristics of gastric cancer in the presence of H.pylori infection was investigated in fifty patients.

Methods: The level of MMP-13 gene expression was measured by quantitative Real-time PCR method and was evaluated between two groups of normal and carcinomatous tissues.

Results: The results showed 30% elevation of MMP-13 expression in tumor tissues. H.pylori infection did not have a significant effect on the expression of MMP-13. There was a correlation between gene expression and tumor type (P value = 0.032). In addition, there was a significant correlation between MMP-13 gene expression and tumor stage in intestinal group (P value = 0.023).

Conclusions: Based on the results, it might be concluded that in intestinal group, immune system plays an important role in reducing gene expression. Results also showed over expression (60%) in diffuse group. These findings suggest that using MMP-13 inhibitors in diffuse group might contribute to the control of tumor growth.
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http://dx.doi.org/10.3233/CBM-160127DOI Listing
March 2018

Study on effect of lomefloxacin on human holo-transferrin in the presence of essential and nonessential amino acids: Spectroscopic and molecular modeling approaches.

Int J Biol Macromol 2017 Apr 20;97:688-699. Epub 2017 Jan 20.

Department of Biochemistry and Biophysics, Faculty of Sciences, Mashhad Branch, Islamic Azad University, Mashhad, Iran. Electronic address:

The purpose of this study was to determine how lomefloxacin (LMF) interacts with human holo-transferrin (HTF) in the presence of two kinds of essential and nonessential amino acids. The investigations were carried out by fluorescence spectroscopy, zeta potential and molecular modeling techniques under imitated physiological conditions. We were able to determine the number of binding sites, the drug binding affinity to HTF in the presence of essential and nonessential amino acids and the quenching source of HTF. The interaction between HTF with LMF suggested that the microenvironment of the Trp residues was altered causing a strong static fluorescence quenching in the binary and ternary systems. The results pointed at the formation of a complex in the binary and ternary systems which caused an enhancement of the RLS intensity that was analyzed using synchronous fluorescence spectroscopy. The density functional theory (DFT) was employed to determine the amino acid residues on HTF that interacted with LMF. Also, Steric and van der Waals forces as well as the contribution of small amounts of hydrogen bonds were stronger or Tyr 71 in chain (b) than for 128 Trp in chain (a) of HTF.
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http://dx.doi.org/10.1016/j.ijbiomac.2017.01.047DOI Listing
April 2017

Multi-spectroscopic and molecular modeling studies of interaction between two different angiotensin I converting enzyme inhibitory peptides from gluten hydrolysate and human serum albumin.

J Biomol Struct Dyn 2017 Dec 26;35(16):3648-3662. Epub 2016 Dec 26.

c Department of Biochemistry and Biophysics, Faculty of Sciences , Mashhad Branch, Islamic Azad University , Mashhad , Iran.

The present study was carried out to characterize Angiotensin-converting enzyme (ACE) inhibitory peptides which are released from the trypsin hydrolysate of wheat gluten protein. The binding of two inhibitory peptide (P and P) to human serum albumin (HSA) under physiological conditions has been investigated by multi-spectroscopic in combination with molecular modeling techniques. Time-resolved and quenching fluorescence spectroscopies results revealed that the quenching of HSA fluorescence by P and P in the binary and ternary systems caused HSA-peptides complexes formation. The results indicated that both peptides quenched the fluorescence intensity of HSA through a static mechanism. The binding affinities and number of binding sites were obtained for the HSA-peptides complexes. The circular dichroism (CD) data revealed that the presence of both peptides increased the α-helix content of HSA and induced the remarkable folding of the polypeptide of the protein. Therefore, the CD data determined that the protein structure has been stabilized in the percent of ACE inhibitory peptides in binary and ternary systems. The binding distances between HSA and both peptides were estimated by the Forster theory, and it was revealed that nonradiative energy transfer from HSA to peptides occurred with a high probability. ITC experiments reveal that, in the absence and presence of P, the dominant forces are electrostatic in binary and ternary systems. Furthermore, molecular modeling studies confirmed the experimental results. Molecular modeling investigation suggested that P bound to the site IA and IIA of HSA in binary and ternary systems, respectively. This study on the interaction of peptides with HSA should prove helpful for realizing the distribution and transportation of food compliments and drugs in vivo, elucidating the action mechanism and dynamics of food compliments and drugs at the molecular level. It should moreover be of great use for understanding the pharmacokinetic and pharmacodynamic mechanism of the food compliments and drugs.
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http://dx.doi.org/10.1080/07391102.2016.1264892DOI Listing
December 2017

Studying the interaction between three synthesized heterocyclic sulfonamide compounds with hemoglobin by spectroscopy and molecular modeling techniques.

J Biomol Struct Dyn 2017 Nov 10;35(15):3250-3267. Epub 2016 Nov 10.

a Faculty of Sciences, Department of Biochemistry and Biophysics, Mashhad Branch , Islamic Azad University , Mashhad , Iran.

The interaction between synthesized heterocyclic benzene sulfonamide compounds, N-(7-benzyl-56-biphenyl-2m-tolyl-7H-pyrrolo[23-d]pyrimidine-4-yl)-benzene sulfonamide (HBS), N-(7-benzyl-56-biphenyl-2-m-tolyl-7H-pyrrolo[23-d] pyrimidine-4-yl)-4-methyl- benzene sulfonamide (HBS), and N-(7-benzyl-56-biphenyl-2-m-tolyl-7H-pyrrolo[23-d]pyrimidine-4-yl)-4-chloro-benzene sulfonamide (HBS) with Hb was studied by fluorescence quenching, zeta potentional, circular dichroism, and molecular modeling techniques. The fluorescence spectroscopy experiments were performed in order to study the conformational changes, possibly due to a discrete reorganization of Trp residues during binding between HBS derivatives and Hb. The variation of the K value suggested that hydrophobic and electrostatic interactions were the predominant intermolecular forces stabilizing the complex. The K ans K values of HBS derivatives with Hb are .6 × 10 and 3 × 10 M for Hb-HBS, 1 × 10 and 4 × 10 M for Hb-HBS, .9 × 10, and 6 × 10 M for Hb-HBS, respectively. The molecular distances between Hb and HBS derivatives in binary and ternary systems were estimated according to Förster's theory of dipole-dipole non-radiation energy transfer. The quantitative analysis data of circular dichroism spectra demonstrated that the binding of the three HBS derivatives to Hb induced conformational changes in Hb. Changes in the zeta potential of the Hb-HBS derivatives complexes demonstrated a hydrophobic adsorption of the anionic ligand onto the surface of Hb as well as both electrostatic and hydrophobic adsorption in the case of the complex. The modeling data thus confirmed the experimental results. This study is expected to provide important insight into the interaction of Hb with three HBS derivatives to use in various toxicological and therapeutic processes.
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http://dx.doi.org/10.1080/07391102.2016.1252283DOI Listing
November 2017

Investigation of the Interaction Between Human Serum Albumin and Two Drugs as Binary and Ternary Systems.

Eur J Drug Metab Pharmacokinet 2016 Dec;41(6):705-721

Department of Biology, Faculty of Sciences, Mashhad Branch, Islamic Azad University, Mashhad, Iran.

Background And Objectives: Human serum albumin (HSA) is the most frequent protein in blood plasma. Albumin transports various compounds, preserves osmotic pressure, and buffers pH. A unique feature of albumin is its ability to bind drugs and other bioactive molecules. However, it is important to consider binary and ternary systems of two pharmaceuticals to estimate the effect of the first drug on the second one and physicochemical properties.

Methods: Different techniques including time-resolved, second-derivative and anisotropy fluorescence spectroscopy, resonance light scattering (RLS), critical induced aggregation concentration (C ), particle size, zeta potential and stability analysis were employed in this assessment to elucidate the binding behavior of Amlodipine and Aspirin to HSA. Moreover, isothermal titration calorimetric techniques were performed and the QSAR properties were applied to analyze the hydration energy and log P. Multiple sequence alignments were also used to predict the structure and biological characteristics of the HSA binding site.

Result: Time-resolved fluorescence spectroscopy showed interaction of both drugs to HSA based on a static quenching mechanism. Subsequently, second-derivative fluorescence spectroscopy presented different values of parameter H in binary and ternary systems, which were suggested that tryptophan was in a more polar environment in the ternary system than in a binary system. Moreover, the polydispersity index and results from mean number measurements revealed that the presence of the second drug caused a decrease in the stability of systems and increased the heterogeneity of complex. It is also, observed that the gradual addition of HSA has led to a marked increase in fluorescence anisotropy (r) of Amlodipine and Aspirin which can be suggested that the drugs were located in a restricted environment of the protein as confirmed by Red Edge Excitation Shift (REES) studies. The isothermal titration calorimetric technique demonstrated that the interaction of the drugs with HSA was an enthalpically-driven process.

Conclusions: The present experiment showed that the binding of Amlodipine and Aspirin to HSA induced a conformational change of HSA. It was also identified that the protein binding of the first drug could be affected by the second drug. Such results can be of great use for understanding the pharmacokinetic and pharmacodynamic mechanisms of drugs.
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http://dx.doi.org/10.1007/s13318-015-0297-yDOI Listing
December 2016

Nanoliposome-mediated targeting of antibodies to tumors: IVIG antibodies as a model.

Int J Pharm 2015 Nov 21;495(1):162-170. Epub 2015 Aug 21.

Biotechnology Research Center, Nanotechnology Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad 91775-1365, Iran. Electronic address:

Monoclonal antibodies are routinely used as tools in immunotherapies against solid tumors. However, administration of monoclonal antibodies may cause undesired side effects due to their accumulation in non-targeted organs. Nanoliposomes of less than 200 nm can target antibodies to tumors by enhanced permeation and retention (EPR) mechanisms. To direct monoclonal antibodies to tumors, nanoliposomes encapsulating intravenous immunoglobulin (IVIG) as a model antibody were prepared. The liposomes had average diameters of 100 nm and encapsulation efficiencies of 31 to 46%. They showed less than 10% release in plasma at 37°C up to seven days. The secondary and tertiary structures of liposome-encapsulated antibodies were analyzed by circular dichroism (CD) spectroscopy. The near and far-UV spectra analyses revealed no obvious conformational changes in the structures of the encapsulated antibodies. The biodistribution of free and liposome-encapsulated iodinated antibodies was investigated in mice bearing C-26 colon carcinoma tumors. The accumulation of liposome-encapsulated antibodies in tumors was significantly greater than that of free antibodies due to the EPR effect. The PEGylated liposomes were more efficient in the delivery of antibodies to the tumor site than non-PEGylated liposomes. We conclude that administration of monoclonal antibodies in PEGylated liposomes is more efficient than administration of non-encapsulated monoclonal antibodies for solid tumor immunotherapy.
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http://dx.doi.org/10.1016/j.ijpharm.2015.08.048DOI Listing
November 2015

Preparation, characterization and molecular modeling of PEGylated human growth hormone with agonist activity.

Int J Biol Macromol 2015 Sep 23;80:400-9. Epub 2015 Jun 23.

Medical Chemistry Department, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran. Electronic address:

In this study, site-specific PEGylated human growth hormone (hGH) was prepared by microbial transglutaminase, modeled and characterized. To this end, the effects of different reaction parameters including reaction media, PEG:protein ratios, reaction time and pH value were investigated. PEG-hGH was purified by size exclusion chromatography method and analyzed by SDS-PAGE, BCA, peptide mapping, ESI and MALDI-TOF-TOF mass spectroscopy methods. Biophysical and biological properties of PEG-hGH were evaluated. Molecular simulation was utilized to provide molecular insight into the protein-receptor interaction. The optimum conditions that were obtained for PEGylation were phosphate buffer with pH of 7.4, 48 h of stirring and PEG:protein ratio of 40:1. By this method, mono-PEG-hGH with high reaction yield was obtained and PEGylation site was at Gln-40 residue. The circular dichroism and fluorescence spectrum indicated that PEGylation did not change the secondary structure while tertiary structure was altered. Upon enzymatic PEGylation, agonistic activity of hGH was preserved; however, Somavert(®), which is prepared by chemical PEGylation, is an antagonist form of protein. These data were confirmed by the total energy of affinity obtained by computational protein-receptor interaction. In conclusion, PEGylation of hGH was led to prepare a novel form of hormone with an agonist activity which merits further investigations.
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http://dx.doi.org/10.1016/j.ijbiomac.2015.06.037DOI Listing
September 2015

Study of the interaction between DNP and DIDS with human hemoglobin as binary and ternary systems: spectroscopic and molecular modeling investigation.

J Biomol Struct Dyn 2016 18;34(1):57-77. Epub 2015 Feb 18.

a Faculty of Sciences, Department of Biochemistry and Biophysics, Mashhad Branch , Islamic Azad University , Mashhad , Iran.

The combination of several drugs is necessary, especially during long-term therapy. A competitive binding of the drugs can cause a decrease in the amount of drugs actually bound to the protein and increase the biologically active fraction of the drug. Here, the interaction between 4,4'-Diisothiocyano-2,2'-stilbenedisulfonic acid (DIDS) and 2,4-Dinitrophenol (DNP) with Hemoglobin (Hb) was investigated by different spectroscopic and molecular modeling techniques. Fluorescence analysis was used to estimate the effect of the DIDS and DNP on Hb as well as to define the binding properties of binary and ternary complexes. The distance r between donor and acceptor was obtained by the FRET and found to be 2.25 and 2.13 nm for DIDS and DNP in binary and 2.08 and 2.07 nm for (Hb-DNP) DIDS and (Hb-DIDS) DNP complexes in ternary systems, respectively. Time-resolved fluorescence spectroscopy confirmed static quenching for Hb in the presence of DIDS and DNP in both systems. Furthermore, an increase in ellipticity values of Hb upon interaction with DIDS and DNP showed secondary structural changes of protein that determine to disrupt of hydrogen bonds and electrostatic interactions. Our results showed that the Hb destabilize in the presence of DIDS and DNP. Molecular modeling of the possible binding sites of DIDS and DNP in binary and ternary systems in Hb confirmed the experimental results.
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http://dx.doi.org/10.1080/07391102.2015.1009946DOI Listing
October 2016

A comparison study of the interaction between β-lactoglobulin and retinol at two different conditions: spectroscopic and molecular modeling approaches.

J Biomol Struct Dyn 2015 Sep 17;33(9):1880-98. Epub 2014 Nov 17.

a Faculty of Sciences, Department of Biochemistry and Biophysics , Mashhad Branch, Islamic Azad University , Mashhad , Iran.

The interaction between bovin β-Lactoglobulin (β-LG) and retinol at two different pH values was investigated by multispectroscopic, zeta potential, molecular modeling, and conductometry measurements. The steady state and polarization fluorescence spectroscopy revealed that complex formation at two different pH values could occur through a remarkable static quenching. According to fluorescence quenching, one set of binding site at pH 2 and two sets of binding sites at pH 7 were introduced for binding of retinol to β-LG that show the enhancement of saturation score of β-LG to retinol in dimmer condition. The polarization fluorescence analysis represented that there is more affinity between β-LG and retinol at pH 7 rather than at pH 2. The effect of retinol on β-LG was studied by UV-visible, circular dichroism (CD), and synchronous fluorescence, which indicated that retinol induced more structural changes on β-LG at pH 7. β-LG-retinol complex formation at two different pH values was recorded via applying resonance light scattering (RLS) and zeta potential. Conductometry and RLS showed two different behaviors of interaction between β-LG and retinol at two different pH values; therefore, dimmer formation played important roles in different behaviors of interaction between β-LG and retinol. The zeta potential was the implied combination of electrostatic and hydrophobic forces which are involved in β-LG-retinol complex at two different pH values, and the hydrophobic interactions play a dominant role in complex formation. Molecular modeling was approved by all experimental results. The acquired results suggested that monomer and dimmer states of β-LG can be induced by retinol with different behaviors.
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http://dx.doi.org/10.1080/07391102.2014.977351DOI Listing
September 2015

Spectroscopic and DFT investigation of interactions between cyclophosphamide and aspirin with lysozyme as binary and ternary systems.

J Biomol Struct Dyn 2015 10;33(8):1669-81. Epub 2014 Oct 10.

a Department of Chemistry , Mashhad Branch, Islamic Azad University , Mashhad , Iran.

Multi-spectroscopic and density functional theory (DFT) calculations was used to study the interaction between cyclophosphamide (CYP) and aspirin (ASA) with lysozyme (LYS). The experimental results showed that fluorescence quenching of LYS by drug was a result of the formation of drug-LYS complex; static quenching was confirmed to result in fluorescence quenching. Modified Stern-Volmer plots of interaction between CYP and ASA with protein in the binary and ternary systems were used to determine the binding parameters. Molecular distances between the donor (LYS) and acceptor (CYP and ASA) for all systems were estimated according to Forster's theory. The quantitative analysis obtained by CD spectra suggested that the presence of ASA and CYP decreased the α-helical content of LYS and induced the destabilizing of it. Theoretical studies on the interaction between LYS with ASA and CYP have been carried out using DFT at the B3LYP/6-31G level in the solvent phase. Binding energy of the mentioned complexes was calculated. It showed that tryptophan (Trp) 62 had the most affinity toward ASA and CYP. Analyzing the calculated results revealed that the five member ring of Trp has a key role in interaction of LYS with ASA and CYP.
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http://dx.doi.org/10.1080/07391102.2014.967299DOI Listing
February 2016

Efficient expression of a soluble lipid transfer protein (LTP) of Platanus orientalis using short peptide tags and structural comparison with the natural form.

Biotechnol Appl Biochem 2015 Mar-Apr;62(2):218-25. Epub 2015 Jan 28.

Immunobiochemistry Lab, Immunology Research Center, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.

Successful recombinant allergen-based immunotherapy has drawn a great deal of attention to use recombinant allergens for new therapeutic and/or diagnostic strategies. The Escherichia coli expression system is frequently used to produce recombinant allergens; however, protein expression in E. coli often results in inclusion bodies. Here, we focused on the expression of two recombinant soluble forms of Pla or 3 using solubility-enhancing peptide tags, human immune deficiency virus type 1 transactivator of transcription core domain and poly-arginine-lysine: rTAT-Pla or 3 and rPoly-Arg-Lys-Pla or 3. Structural characteristics and IgE reactivity of purified recombinant proteins were compared with natural Pla or 3 (nPla or 3) isolated from Platanus orientalis using circular dichroism spectra, fluorescence spectroscopy, and immunoblotting. Likewise, intrinsic viscosity and Stokes radius of the natural and recombinant Pla or 3 allergens were determined to analyze structural compactness in aqueous media. The results indicate high-level solubility and efficient expression of the fusion proteins (rTAT-Pla or 3 and rPoly-Arg-Lys-Pla or 3) compared with the wild-type recombinant. Furthermore, the similar structural characteristics and IgE-binding activities of the fusion proteins to nPla or 3 provide a promising tool for allergy diagnosis and treatment.
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http://dx.doi.org/10.1002/bab.1235DOI Listing
January 2016