3,163 results match your criteria anionic site

Room temperature crystallography of human acetylcholinesterase bound to a substrate analogue 4K-TMA: Towards a neutron structure.

Curr Res Struct Biol 2021 6;3:206-215. Epub 2021 Sep 6.

Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.

Acetylcholinesterase (AChE) catalyzes hydrolysis of acetylcholine thereby terminating cholinergic nerve impulses for efficient neurotransmission. Human AChE (hAChE) is a target of nerve agent and pesticide organophosphorus compounds that covalently attach to the catalytic Ser203 residue. Reactivation of inhibited hAChE can be achieved with nucleophilic antidotes, such as oximes. Read More

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September 2021

Adoptive CD8T-cell grafted with liposomal immunotherapy drugs to counteract the immune suppressive tumor microenvironment and enhance therapy for melanoma.

Nanoscale 2021 Sep 16. Epub 2021 Sep 16.

State Key Laboratory of Biotherapy/Collaborative Innovation Centre of Biotherapy, West China Hospital, Sichuan University, 17#, Section 3, Ren Min Nan Road, Chengdu, Sichuan, 610041, PR China.

The immunosuppressive tumor microenvironment has become a formidable obstacle to the treatment of tumors using adoptive T cell therapy, in particular solid tumors. For the purposes of addressing this issue, effector OT-1 CD8T cells conjugated with liposomal immune regulators (CD8-T-LP-CpG/CD8-T-LP-BMS-202) were developed. An anionic liposome formulation was employed to avoid T cell aggregation and prevent unfavorable side-effects. Read More

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September 2021

Cationic polythiophene-anionic fullerene pair in water and water-dioxane: studies on hydrogen bonding capabilities, kinetic and thermodynamic properties.

Phys Chem Chem Phys 2021 Sep 15. Epub 2021 Sep 15.

Department of Chemistry, Turku University Centre for Materials and Surfaces (MatSurf), Vatselankatu 2, FI-20014 Turku, Finland.

Despite the vast array of solution- and solid-state bio-analytical, bioelectronic and optoelectronic applications of cationic polythiophenes (CPTs), the number of studies focused on the role of hydrogen bonding (H-bonding) between these and other molecules is scarce, regardless of whether H-bonding is expected to play an important role in several such applications. Also, despite the advantages of using cosolvents to systematically examine the molecular interactions, there are no such studies for CPTs to our knowledge. This work presents a steady-state UV-vis/fluorescence spectroscopic, kinetic and thermodynamic study on the H-bonding interactions between a water-soluble, cationic-anionic (isothiouronium-tetraphosphonate), polythiophene-fullerene donor-acceptor pair with two-point, charge-assisted H-bonding (CAHB) capabilities, tuned using water or a 1,4-dioxane-water mixture (W-DI). Read More

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September 2021

Polyethyleneimine impregnated alginate capsule as a high capacity sorbent for the recovery of monovalent and trivalent gold.

Sci Rep 2021 Sep 8;11(1):17836. Epub 2021 Sep 8.

Division of Semiconductor and Chemical Engineering, Jeonbuk National University (Formerly Chonbuk National University), Jeonju, Jeonbuk, 54896, South Korea.

For the first time, a polyethyleneimine-impregnated alginate capsule (PEIIAC) with a high adsorption capacity is developed for the recovery of monovalent and trivalent gold from an acidic solution. The strategy results in a new type of adsorbent, polyethyleneimine impregnated alginate capsule (PEIIAC) with a core-shell structure having a large number of amine groups as cationic binding site, facilitating maximum uptake of anionic auric chloride. The maximum uptake of PEIIAC was 3078 and 929 mg/g for Au (III) and Au (I), respectively, are recordable compared to other reported adsorbents to date. Read More

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September 2021

Electrostatic Drivers of GPx4 Interactions with Membrane, Lipids, and DNA.

Biochemistry 2021 Sep 7. Epub 2021 Sep 7.

Department of Chemistry, Virginia Commonwealth University, Richmond, Virginia 23284, United States.

Glutathione peroxidase 4 (GPx4) serves as the only enzyme that protects membranes through the reduction of lipid hydroperoxides, preventing membrane oxidative damage and cell death through ferroptosis. Recently, GPx4 has gained attention as a therapeutic target for cancer through inhibition and as a target for inflammatory diseases through activation. In addition, GPx4 isoforms perform several distinct moonlighting functions including cysteine cross-linking of protamines during sperm cell chromatin remodeling, a function for which molecular and structural details are undefined. Read More

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September 2021

Anticoagulant Dodecapeptide Suppresses Thrombosis In Vivo by Inhibiting the Thrombin Exosite-I Binding Site.

J Agric Food Chem 2021 Sep 7. Epub 2021 Sep 7.

School of Food Science and Technology, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian 116034, China.

Thrombin is a crucial regulatory serine protease in hemostasis and thrombosis and has been a therapeutic target of thrombotic events. A novel oyster-derived thrombin inhibitory dodecapeptide (IEELEELEAER, P-2-CG) was identified and characterized. P-2-CG prolonged thrombin time from 9. Read More

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September 2021

Novel tacrine-based acetylcholinesterase inhibitors as potential agents for the treatment of Alzheimer's disease: Quinolotacrine hybrids.

Mol Divers 2021 Sep 7. Epub 2021 Sep 7.

Department of Medicinal Chemistry, School of Pharmacy, Hamadan University of Medical Sciences, Hamadan, Iran.

A new series of quinolotacrine hybrids including cyclopenta- and cyclohexa-quinolotacrine derivatives were designed, synthesized, and assessed as anti-cholinesterase (ChE) agents. The designed derivatives indicated higher inhibitory effect on the acetylcholinesterase (AChE) with IC values of 0.285-100 µM compared to butyrylcholinesterase (BChE) with IC values of > 100 µM. Read More

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September 2021

Guidelines for surfactant selection to treat petroleum hydrocarbon-contaminated soils.

Environ Sci Pollut Res Int 2021 Sep 3. Epub 2021 Sep 3.

Departamento de Ingeniería Química y Ambiental, Escuela Técnica Superior de Ingeniería, Universidad de Sevilla, Camino de los Descubrimientos, s/n, 41092, Sevilla, Spain.

The present study determined the most effective surfactants to remediate gasoline and diesel-contaminated soil integrating information from soil texture and soil organic matter. Different ranges for aliphatic and aromatic hydrocarbons (> C6-C8, > C8-C10, > C10-C12, > C12-C16, > C16-C21, and > C21-C35) in gasoline and diesel fuel were analyzed. This type of analysis has been investigated infrequently. Read More

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September 2021

Cation complexation by mucoid Pseudomonas aeruginosa extracellular polysaccharide.

PLoS One 2021 2;16(9):e0257026. Epub 2021 Sep 2.

School of Food Science & Nutrition, University of Leeds, Leeds, United Kingdom.

Mucoid Pseudomonas aeruginosa is a prevalent cystic fibrosis (CF) lung colonizer, producing an extracellular matrix (ECM) composed predominantly of the extracellular polysaccharide (EPS) alginate. The ECM limits antimicrobial penetration and, consequently, CF sufferers are prone to chronic mucoid P. aeruginosa lung infections. Read More

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September 2021

Self-assembly of ionic and non-ionic surfactants in type IV cerium nitrate and urea based deep eutectic solvent.

J Chem Phys 2021 Aug;155(8):084902

Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AX, United Kingdom.

Understanding and manipulating micelle morphology are key to exploiting surfactants in various applications. Recent studies have shown surfactant self-assembly in a variety of Deep Eutectic Solvents (DESs) where both the nature of surfactants and the interaction of the surfactant molecule with the solvent components influence the size, shape, and morphology of the micelles formed. So far, micelle formation has only been reported in type III DESs, consisting solely of organic species. Read More

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Targeted and intracellular delivery of protein therapeutics by a boronated polymer for the treatment of bone tumors.

Bioact Mater 2022 Jan 10;7:333-340. Epub 2021 Jun 10.

Shanghai Key Laboratory of Regulatory Biology, School of Life Sciences, East China Normal University, Shanghai, 200241, China.

The treatment of malignant bone tumors by chemotherapeutics often receives poor therapeutic response due to the specific physiological bone environment, and thus calls for the development of new therapeutic options. Here, we reported a bone-targeted protein nanomedicine for this purpose. Saporin, a toxin protein, was co-assembled with a boronated polymer for intracellular protein delivery, and the formed nanoparticles were further coated with an anionic polymer poly (aspartic acid) to shield the positive charges on nanoparticles and provide the bone targeting function. Read More

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January 2022

Reduced bioaccumulation of fluorotelomer sulfonates and perfluoroalkyl acids in earthworms (Eisenia fetida) from soils amended with modified clays.

J Hazard Mater 2021 Aug 21;423(Pt A):126999. Epub 2021 Aug 21.

Department of Civil Engineering, McGill University, Montréal, QC, Canada. Electronic address:

Soils contaminated by per- and polyfluoroalkyl substances (PFAS) pose long-term sources to adjacent water bodies and soil invertebrates. The study investigated the stabilization using a modified clay adsorbent (FLUORO-SORB100®) in reducing the bioaccumulation of 13 anionic PFAS by earthworms (Eisenia fetida), as compared to coal-based granular activated carbon. The target PFAS included four perfluoroalkyl sulfonates such as perfluorooctane sulfonate (PFOS), six perfluoroalkyl carboxylates (e. Read More

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Bacteriophage Delivery Systems Based on Composite PolyHIPE/Nanocellulose Hydrogel Particles.

Polymers (Basel) 2021 Aug 9;13(16). Epub 2021 Aug 9.

Department of Chemical Engineering and Technical Safety, Faculty for Chemistry and Chemical Technology, University of Ljubljana, SI-1000 Ljubljana, Slovenia.

The role of bacteriophage therapy in medicine has recently regained an important place. Oral phage delivery for gastrointestinal treatment, transport through the stomach, and fast release in the duodenum is one of such applications. In this work, an efficient polyHIPE/hydrogel system for targeted delivery of bacteriophages with rapid release at the target site is presented. Read More

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Peptide-Assisted Nucleic Acid Delivery Systems on the Rise.

Int J Mol Sci 2021 Aug 23;22(16). Epub 2021 Aug 23.

Department of Chemistry, University of Basel, Mattenstrasse 24a, 4058 Basel, Switzerland.

Concerns associated with nanocarriers' therapeutic efficacy and side effects have led to the development of strategies to advance them into targeted and responsive delivery systems. Owing to their bioactivity and biocompatibility, peptides play a key role in these strategies and, thus, have been extensively studied in nanomedicine. Peptide-based nanocarriers, in particular, have burgeoned with advances in purely peptidic structures and in combinations of peptides, both native and modified, with polymers, lipids, and inorganic nanoparticles. Read More

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Synthesis, Biological Evaluation, and In Silico Studies of New Acetylcholinesterase Inhibitors Based on Quinoxaline Scaffold.

Molecules 2021 Aug 12;26(16). Epub 2021 Aug 12.

Department of Pharmaceutical Chemistry, Faculty of Pharmaceutical Sciences, Prince of Songkla University, Hat Yai 90112, Songkhla, Thailand.

A quinoxaline scaffold exhibits various bioactivities in pharmacotherapeutic interests. In this research, twelve quinoxaline derivatives were synthesized and evaluated as new acetylcholinesterase inhibitors. We found all compounds showed potent inhibitory activity against acetylcholinesterase (AChE) with IC values of 0. Read More

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Protonation States of Molecular Groups in the Chromophore-Binding Site Modulate Properties of the Reversibly Switchable Fluorescent Protein rsEGFP2.

J Phys Chem Lett 2021 Sep 23;12(34):8263-8271. Epub 2021 Aug 23.

Department of Chemistry, Lomonosov Moscow State University, Moscow 119991, Russia.

The role of protonation states of the chromophore and its neighboring amino acid side chains of the reversibly switching fluorescent protein rsEGFP2 upon photoswitching is characterized by molecular modeling methods. Numerous conformations of the chromophore-binding site in computationally derived model systems are obtained using the quantum chemistry and QM/MM approaches. Excitation energies are computed using the extended multiconfigurational quasidegenerate perturbation theory (XMCQDPT2). Read More

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September 2021

RGD-pectin microfiber patches for guiding muscle tissue regeneration.

J Biomed Mater Res A 2021 Aug 23. Epub 2021 Aug 23.

Department of Chemistry, Materials and Chemical Engineering "G. Natta", Politecnico di Milano, Milan, Italy.

Opportunely arranged microscaled fibers offer an attractive 3D architecture for tissue regeneration as they may enhance and stimulate specific tissue regrowth. Among different scaffolding options, encapsulating cells in degradable hydrogel microfibers appears as particularly attractive strategy. Hydrogel patches, in fact, offer a highly hydrated environment, allow easy incorporation of biologically active molecules, and can easily adapt to implantation site. Read More

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Identification and assessment of cardiolipin interactions with inner membrane proteins.

Sci Adv 2021 Aug 20;7(34). Epub 2021 Aug 20.

Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK.

Integral membrane proteins are localized and/or regulated by lipids present in the surrounding bilayer. While bacteria have relatively simple membranes, there is ample evidence that many bacterial proteins bind to specific lipids, especially the anionic lipid cardiolipin. Here, we apply molecular dynamics simulations to assess lipid binding to 42 different inner membrane proteins. Read More

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Stabilizing Transition Metal Vacancy Induced Oxygen Redox by Co /Co Redox and Sodium-Site Doping for Layered Cathode Materials.

Angew Chem Int Ed Engl 2021 Sep 31;60(40):22026-22034. Epub 2021 Aug 31.

Department of Materials Science, Fudan University, Shanghai, 200433, P. R. China.

Anionic redox is an effective way to boost the energy density of layer-structured metal-oxide cathodes for rechargeable batteries. However, inherent rigid nature of the TMO (TM: transition metals) subunits in the layered materials makes it hardly tolerate the inner strains induced by lattice glide, especially at high voltage. Herein, P2-Na Mg [Mn Co Mg □ ]O (□: TM vacancy) is designed that contains vacancies in TM sites, and Mg ions in both TM and sodium sites. Read More

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September 2021

Rifampicin-Liposomes for Infection Treatment: Intracellular Uptake and Antibacterial Activity Evaluation.

Pharmaceutics 2021 Jul 13;13(7). Epub 2021 Jul 13.

Dipartimento di Chimica e Tecnologie del Farmaco, Sapienza Università di Roma-Piazzale Aldo Moro 5, 00185 Rome, Italy.

Treatment of pulmonary infections caused by are extremely difficult to treat, as this species is naturally resistant to many common antibiotics. Liposomes are vesicular nanocarriers suitable for hydrophilic and lipophilic drug loading, able to deliver drugs to the target site, and successfully used in different pharmaceutical applications. Moreover, liposomes are biocompatible, biodegradable and nontoxic vesicles and nebulized liposomes are efficient in targeting antibacterial agents to macrophages. Read More

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Cys-labeling kinetics of membrane protein GlpG: a role for specific SDS binding and micelle changes?

Biophys J 2021 Aug 8. Epub 2021 Aug 8.

Interdisciplinary Nanoscience Center and Department of Molecular Biology and Genetics, Aarhus C, Denmark.

Empirically, α-helical membrane protein folding stability in surfactant micelles can be tuned by varying the mole fraction MF of anionic (sodium dodecyl sulfate (SDS)) relative to nonionic (e.g., dodecyl maltoside (DDM)) surfactant, but we lack a satisfying physical explanation of this phenomenon. Read More

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Structural insights into the mechanism of pH-selective substrate specificity of the polysaccharide lyase Smlt1473.

J Biol Chem 2021 Aug 3:101014. Epub 2021 Aug 3.

School of Biological Sciences, National Institute of Science Education and Research, Bhubaneswar, 752050, Odisha, India; Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, Maharashtra, India. Electronic address:

Polysaccharide lyases (PLs) are a broad class of microbial enzymes that degrade anionic polysaccharides. Equally broad diversity in their polysaccharide substrates has attracted interest in biotechnological applications such as biomass conversion to value-added chemicals and microbial biofilm removal. Unlike other PLs, Smlt1473 present in the clinically-relevant Stenotrophomonas maltophilia strain K279a demonstrates a wide range of pH-dependent substrate specificities towards multiple, diverse polysaccharides: hyaluronic acid (pH 5. Read More

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Following in Emil Fischer's Footsteps: A Site-Selective Probe of Glucose Acid-Base Chemistry.

J Phys Chem A 2021 Aug 30;125(32):6881-6892. Epub 2021 Jul 30.

Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany.

Liquid-jet photoelectron spectroscopy was applied to determine the first acid dissociation constant (p) of aqueous-phase glucose while simultaneously identifying the spectroscopic signature of the respective deprotonation site. Valence spectra from solutions at pH values below and above the first p reveal a change in glucose's lowest ionization energy upon the deprotonation of neutral glucose and the subsequent emergence of its anionic counterpart. Site-specific insights into the solution-pH-dependent molecular structure changes are also shown to be accessible via C 1s photoelectron spectroscopy. Read More

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Nanopore Stochastic Sensing Based on Non-covalent Interactions.

Anal Chem 2021 08 28;93(31):10974-10981. Epub 2021 Jul 28.

Department of Chemistry, Illinois Institute of Technology, 3101 S. Dearborn Street, Chicago, Illinois 60616, United States.

A variety of species could be detected by using nanopores engineered with various recognition sites based upon non-covalent interactions, including electrostatic, aromatic, and hydrophobic interactions. The existence of these engineered non-covalent bonding sites was supported by the single-channel recording technique. The advantage of the non-covalent interaction-based sensing strategy was that the recognition site of the engineered nanopore was not specific for a particular molecule but instead selective for a class of species (e. Read More

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Aminotroponiminates: Impact of the NO Functional Group on Coordination, Isomerisation, and Backbone Substitution.

Chemistry 2021 Jul 27. Epub 2021 Jul 27.

Institut für Anorganische Chemie, Fakultät für Chemie und Pharmazie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany.

Aminotroponiminate (ATI) ligands are a versatile class of redox-active and potentially cooperative ligands with a rich coordination chemistry that have consequently found a wide range of applications in synthesis and catalysis. While backbone substitution of these ligands has been investigated in some detail, the impact of electron-withdrawing groups on the coordination chemistry and reactivity of ATIs has been little investigated. We report here Li, Na, and K salts of an ATI ligand with a nitro-substituent in the backbone. Read More

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Potential of nafimidone derivatives against co-morbidities of epilepsy: In vitro, in vivo, and in silico investigations.

Drug Dev Res 2021 Jul 22. Epub 2021 Jul 22.

Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Jagiellonian University Medical College, Krakow, Poland.

Nafimidone is known for its clinical antiepileptic effects and alcohol derivatives of nafimidone were reported be potent anticonvulsants. These compounds are structurally similar to miconazole, which is known to inhibit cholinesterases, protect neurons, and ameliorate cognitive decline. Herein, we aimed to reveal the potential of three nafimidone alcohol esters (5 g, 5i, and 5 k), which were previously reported for their anticonvulsant effects, against co-morbidities of epilepsy such as inflammatory and neuropathic pain, cognitive and behavioral deficits, and neuron death, and understand their roles in related pathways such as γ-butyric acid type A (GABA ) receptor and cholinesterases using in vitro, in vivo and in silico methods. Read More

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An artificial membrane binding protein-polymer surfactant nanocomplex facilitates stem cell adhesion to the cartilage extracellular matrix.

Biomaterials 2021 09 28;276:120996. Epub 2021 Jun 28.

School of Cellular and Molecular Medicine, University of Bristol, BS8 1TD, UK; BrisSynBio Synthetic Biology Research Centre, University of Bristol, BS8 1TQ, UK. Electronic address:

One of the major challenges within the emerging field of injectable stem cell therapies for articular cartilage (AC) repair is the retention of sufficient viable cell numbers at the site of injury. Even when delivered via intra-articular injection, the number of stem cells retained at the target is often low and declines rapidly over time. To address this challenge, an artificial plasma membrane binding nanocomplex was rationally designed to provide human mesenchymal stem cells (hMSCs) with increased adhesion to articular cartilage tissue. Read More

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September 2021

Spontaneous lipid binding to the nicotinic acetylcholine receptor in a native membrane.

J Chem Phys 2021 May;154(18):185102

Center for Computational and Integrative Biology, Rutgers University-Camden, Camden, New Jersey 08102, USA.

The nicotinic acetylcholine receptor (nAChR) and other pentameric ligand-gated ion channels are native to neuronal membranes with an unusual lipid composition. While it is well-established that these receptors can be significantly modulated by lipids, the underlying mechanisms have been primarily studied in model membranes with few lipid species. Here, we use coarse-grained molecular dynamics simulation to probe specific binding of lipids in a complex quasi-neuronal membrane. Read More

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Distribution of free amino acids and mRNA expression of their corresponding transporters in the intestinal mucosa of goats feeding on a corn grain versus corn gluten diet.

J Sci Food Agric 2021 Jul 4. Epub 2021 Jul 4.

CAS Key Laboratory of Agro-Ecological Processes in Subtropical Region, National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Hunan Provincial Key Laboratory of Animal Nutritional Physiology and Metabolic Process, Institute of Subtropical Agriculture, The Chinese Academy of Sciences, Changsha, P. R. China.

Background: Intestinal amino acid (AA) chemosensing has been implicated in the regulation of AA absorption, nitrogen metabolism and hormone release, thereby playing an indispensable role in maintaining metabolic homeostasis in mammals. The objective of this experiment was to study the distribution of free AA and the expression of AA transporting related genes along the small and large intestines of Liuyang black goats, together with the effects of dietary corn grain replaced by dietary corn gluten feed (CGF).

Results: The CGF replacement did not alter (P > 0. Read More

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In silico, theoretical biointerface analysis and in vitro kinetic analysis of amine compounds interaction with acetylcholinesterase and butyrylcholinesterase.

Int J Biol Macromol 2021 Aug 1;185:750-760. Epub 2021 Jul 1.

Department of Biochemistry, Periyar University, Salem, Tamil Nadu 636011, India. Electronic address:

Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) are considered important target for drug design against Alzheimer's disease. In the present study in silico analysis; theoretical analysis of biointerface between ligand and interacting amino acid residues of proteins; and in vitro analysis of enzyme inhibition kinetics were carried out to delineate the inhibitory property of amine compounds against AChE/BChE. High throughput virtual screening of amine compounds identified three compounds (2-aminoquinoline, 2-aminobenzimidazole and 2-amino-1-methylbenzimidazole) that best interacted with AChE/BChE. Read More

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