Department of Biochemistry and Molecular Biology, University of Rajshahi, Bangladesh
Rajshahi | Bangladesh
Primary Affiliation: Department of Biochemistry and Molecular Biology, University of Rajshahi, Bangladesh - Rajshahi , Bangladesh
7PubMed Central Citations
Int J Biol Macromol 2019 Mar 4;125:92-98. Epub 2018 Dec 4.
Department of Biochemistry and Molecular Biology, Faculty of Science, University of Rajshahi, Rajshahi 6205, Bangladesh. Electronic address:
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Int J Biol Macromol 2019 Mar 26;124:819-827. Epub 2018 Nov 26.
Laboratory of Glycobiology and Marine Biochemistry, Department of Life and Environmental System Science, Graduate School of NanoBiosciences, Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama 236-0027, Japan. Electronic address:
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Int J Biol Macromol. 2017 Apr 28;102:952-959.
International Journal of Biological Macromolecules
A lectin was isolated from the tuberous rhizome of Keampferia rotunda by using different chromatographic methods with the molecular weight of 21±1kDa. The lectin contained highest percentage of leucine and lowest percentage of tryptophan residues as determined by LC-MS. The lectin agglutinated mice and human erythrocytes and the hemagglutination activity was inhibited by Methyl-β-d-galactopyranoside. The lectin did not lose its activity in the presence of urea but the activity abolished completely when treated with EDTA. The lectin exhibited its activity at the pH ranging from 6.0 to 9.0 and in a temperature range of 30-80°C. Antiproliferative activity was studied against Ehrlich ascites carcinoma (EAC) and U87 cell lines. No inhibitory effect was observed against U87 cell line whereas 43.7% cell growth inhibition was observed in vitro against EAC cells at 160μg/ml. The lectin was injected (i.p.) in EAC bearing Swiss albino mice at the doses of 3.0 and 6.0mg/kg/day for five consecutive days and 41 and 59% of EAC cell growth inhibition was observed, respectively. The cell growth inhibition was due to the induction of apoptosis in the EAC cells which was confirmed by cell morphological study, caspase-3 inhibitor and apoptosis-related gene expression.
Int J Biosciences. 2016; 9 (6), 187-192.
International Journal of Biosciences
A Trichosanthes cucumerina seed lectin (TCSL) was purified previously that showed potent inhibitory effects against Ehrlich ascites carcinoma (EAC) cells in vivo in mice. In the present study, the lectin was treated with guanidine-HCl for 2 and 4h in the presence and absence of Ca2+ and changes in the tryptophan fluorescence shift were monitored by fluorescence spectroscopy. It was found that the lectin stability was increased in the presence of Ca2+. Although the denaturant changed the environment of tryptophan residue, it did not affect the binding sites of TCSL as red blood cells became agglutinated after the treatment with EDTA. Besides the agglutination of three pathogenic bacterial species, the lectin also partially inhibited the growth of Salmonella enteritidis and Staphylococcus aureus.
Glyconj J, 2016; 34 (1), 85-94
An N-acetyl sugar-binding lectin (termed iNoL) displaying cytotoxic activity against human cancer cells was isolated from the slipper lobster Ibacus novemdentatus (family Scyllaridae). iNoL recognized monosaccharides containing N-acetyl group, and glycoproteins (e.g., BSM) containing oligosaccharides with N-acetyl sugar. iNoL was composed of five subunits (330, 260, 200, 140, and 30 kDa), which in turn consisted of 70-, 40-, and 30-kDa polypeptides held together by disulfide bonds. Electron microscopic observations and gel permeation chromatography indicated that iNoL was a huge (500-kDa) molecule and had a polygonal structure under physiological conditions. iNoL displayed cytotoxic (apoptotic) effects against human cancer cell lines MCF7 and T47D (breast), HeLa (ovarian), and Caco2 (colonic), through incorporation (internalization) into cells. The lectin was transported into lysosomes via endosomes. Its cytotoxic effect and incorporation into cells were inhibited by the co-presence of N-acetyl-D-mannosamine (ManNAc). Treatment of HeLa cells with iNoL resulted in DNA fragmentation and chromatin condensation, through activation of caspase-9 and −3. In summary, the novel crustacean lectin iNoL is incorporated into mammalian cancer cells through glycoconjugate interaction, and has cytotoxic (apoptotic) effects.
Sci Rep. 2016; 6, 28344, 2016.
MytiLec is a lectin, isolated from bivalves, with cytotoxic activity against cancer cell lines that express globotriaosyl ceramide, Galα(1,4)Galβ(1,4)Glcα1-Cer, on the cell surface. Functional analysis shows that the protein binds to the disaccharide melibiose, Galα(1,6)Glc, and the trisaccharide globotriose, Galα(1,4)Galβ(1,4)Glc. Recombinant MytiLec expressed in bacteria showed the same haemagglutinating and cytotoxic activity against Burkitt’s lymphoma (Raji) cells as the native form. The crystal structure has been determined to atomic resolution, in the presence and absence of ligands, showing the protein to be a member of the β-trefoil family, but with a mode of ligand binding unique to a small group of related trefoil lectins. Each of the three pseudo-equivalent binding sites within the monomer shows ligand binding, and the protein forms a tight dimer in solution. An engineered monomer mutant lost all cytotoxic activity against Raji cells, but retained some haemagglutination activity, showing that the quaternary structure of the protein is important for its cellular effects.
Mar Drugs, 2016; 14, 92, 2016.
MytiLec is an α-D-galactose-binding lectin with a unique primary structure isolated from the Mediterranean mussel (Mytilus galloprovincialis). The lectin adopts a β-trefoil fold that is also found in the B-sub-unit of ricin and other ricin-type (R-type) lectins. We are introducing MytiLec(-1) and its two variants (MytiLec-2 and -3), which both possess an additional pore-forming aerolysin-like domain, as members of a novel multi-genic "mytilectin family" in bivalve mollusks. Based on the full length mRNA sequence (911 bps), it was possible to elucidate the coding sequence of MytiLec-1, which displays an extended open reading frame (ORF) at the 51 end of the sequence, confirmed both at the mRNA and at the genomic DNA sequence level. While this extension could potentially produce a polypeptide significantly longer than previously reported, this has not been confirmed yet at the protein level. MytiLec-1 was revealed to be encoded by a gene consisting of two exons and a single intron. The first exon comprised the 51 UTR and the initial ATG codon and it was possible to detect a putative promoter region immediately ahead of the transcription start site in the MytiLec-1 genomic locus. The remaining part of the MytiLec-1 coding sequence (including the three sub-domains, the 31 UTR and the poly-A signal) was included in the second exon. The bacteriostatic activity of MytiLec-1 was determined by the agglutination of both Gram-positive and Gram-negative bacteria, which was reversed by the co-presence of α-galactoside. Altogether, these data support the classification of MytiLec-1 as a member of the novel mytilectin family and suggest that this lectin may play an important role as a pattern recognition receptor in the innate immunity of mussels.
Molecules 2016 Jan 21;21(1):129. Epub 2016 Jan 21.
Laboratories of Glycobiology & Marine Biochemistry and Molecular Toxicology, Department of Life and Environmental System Science, Graduate School of NanoBio Sciences, Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama 236-0027, Japan.
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Mar Drugs 2015 Dec 14;13(12):7377-89. Epub 2015 Dec 14.
Department of Life and Environmental System Science, Graduate School of NanoBio Sciences, Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama 236-0027, Japan.
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Mar Drugs. 2015 Dec 14; 13(12):7377-7389
MytiLec; a novel lectin isolated from the Mediterranean mussel (Mytilus galloprovincialis); shows strong binding affinity to globotriose (Gb3: Galα1-4Galβ1-4Glc). MytiLec revealed β-trefoil folding as also found in the ricin B-subunit type (R-type) lectin family, although the amino acid sequences were quite different. Classification of R-type lectin family members therefore needs to be based on conformation as well as on primary structure. MytiLec specifically killed Burkitt's lymphoma Ramos cells, which express Gb3. Fluorescein-labeling assay revealed that MytiLec was incorporated inside the cells. MytiLec treatment of Ramos cells resulted in activation of both classical MAPK/ extracellular signal-regulated kinase and extracellular signal-regulated kinase (MEK-ERK) and stress-activated (p38 kinase and JNK) Mitogen-activated protein kinases (MAPK) pathways. In the cells, MytiLec treatment triggered expression of tumor necrosis factor (TNF)-α (a ligand of death receptor-dependent apoptosis) and activation of mitochondria-controlling caspase-9 (initiator caspase) and caspase-3 (activator caspase). Experiments using the specific MEK inhibitor U0126 showed that MytiLec-induced phosphorylation of the MEK-ERK pathway up-regulated expression of the cyclin-dependent kinase inhibitor p21, leading to cell cycle arrest and TNF-α production. Activation of caspase-3 by MytiLec appeared to be regulated by multiple different pathways. Our findings, taken together, indicate that the novel R-type lectin MytiLec initiates programmed cell death of Burkitt’s lymphoma cells through multiple pathways (MAPK cascade, death receptor signaling; caspase activation) based on interaction of the lectin with Gb3-containing glycosphingolipid-enriched microdomains on the cell surface.
Int J Org Chem. 2015 Dec 4; 5(4): 232-245.
International Journal of Organic Chemistry
A new N-acetylsulfanilylation series of uridine have been synthesized in good yield using direct acylation method and afforded the 5’-O-N-acetylsulfanilyluridine. In order to obtain newer products, the 5’-O-N-acetylsulfanilyluridine derivative was further transformed to a series of 2’,3’-di-O-acyl derivatives containing a wide variety of functionalities in a single molecular framework. The chemical structures of the newly synthesized compounds were confirmed on the basis of their FTIR, 1H-NMR spectroscopy, physicochemical properties and elemental analysis. All the synthesized uridine derivatives were tested for their in vitro antibacterial activity against six human pathogenic bacterial strains and for comparison standard antibiotic Ampicillin was also determined. The study revealed that the selectively acylated deriva-tives 5’-O-N-acetylsulfanilyl-2’,3’-di-O-lauroyluridine and 5’-O-N-acetylsulfanilyl-2’,3’-di-O-pivaloyluridine showed highest inhibition against Staphylococcus aureus and Bacillus cereus, respectively. We also observed that the introduction of hexanoyl, decanoyl, lauroyl, myristoyl and pivaloyl groups, the antibacterial functionality of the compound uridine increases. Another noteworthy observation was that the uridine derivatives were found comparatively more effective against Gram-positive microorganisms than that of Gram-negative microorganisms. In addition, the test chemicals were also tested for cyto-toxicity by brine shrimp lethality bioassay and compounds showed different rate mortality with different concentrations.
Hacettepe J Biol Chem. 2015; 43(4): 309-322.
Hacettepe Journal of Biology and Chemistry
In the present investigation, a new series of methyl 6-O-cinnamoyl-α-D-glucopyranoside derivatives were synthesized by the reaction of methyl α-D-glucopyranoside (1) with various non-traditional acylating agents in pyridine at -5o C. For this purpose, firstly, selective cinnamoylation of methyl α-D-glucopyranoside (1) has been carried out by the direct acylation method and afforded the methyl 6-O-cinnamoyl-α-D-glucopyranoside (2) in good yield. Secondly, in order to obtain newer products for antimicrobial screening studies, the 6-O-cinnamoyl derivative was further transformed to a series of 2,3,4-tri-O-acyl derivatives (4-14) containing a wide variety of functionalities in a single molecular framework. The structures of the newly synthesized compounds were characterized by IR, NMR and physicochemical properties analyses. All the compounds were evaluated for their in vitro antibacterial and antifungal activities using the disc diffusion and food poisoning methods. The study revealed that the compound methyl 6-O-cinnamoyl-2,3,4-tri-O-decanoyl-α-D-glucopyranoside (7) showed the highest inhibition activity against both Gram (+) B. subtilis and Gram (-) P. aeruginosa microorganisms. The tested compound methyl 6-O-cinnamoyl-2,3,4-tri-O-lauroyl-α-D-glucopyranoside (8) exhibited maximum mycelial growth inhibition against A. niger fungi. The acylated derivatives were found to be more effective against the fungal strains than those of the bacterial pathogens. This is the first report of the antimicrobial activity of the selected chemicals against the selected pathogens.
International Journal of Biological Macromolecules
Int J Phar Sci Res. 2015 Oct 1; 6(10):4277-4283
International Journal of Pharmaceutical Sciences and Research
A simple, reproducible and economical UV spectrophotometric method was developed for determining the potency of ciprofloxacin HCl in tablet dosage forms marketed in Bangladesh. Standard curves of ciprofloxacin HCl in the media of 0.1N HCl and distilled water were obtained by plotting absorbance versus concentration where calibration curve was found to be linear (r2>0.99). The average potency value for seven tablet samples (C1, C2, C3, C4, C5, C6 and C7) measured by HPLC method was 99.08±0.60% for 0.1 N HCl taking the absorbance at 277nm and 98.76±0.69% in case of distilled water at 276 nm, whether the value determined by this UV spectrophotometric method was quite satisfactory being 98.15±0.76% and 97.64±0.71%, respectively. In a separate experiment, efficiency of this method in practice was checked by determining the thermostability of ciprofloxacin HCl to find out how severely that degrades in high temperature conditions. Development of such economical UV spectrophotometric method will encourage low-investing pharmaceutical companies to employ this alternative method in quality control laboratories for routine analysis of ciprofloxacin HCl.
Ann Mar Biol Res 2(1): 1005
Annals of Marine Biology and Research
Glycan expression pattern in the tissue of marine organisms can provide useful information about glycobiology from different angles. The diversity of oligosaccharide structures present in the annelid from the Pacific Ocean, Perinereis nuntia ver. vallata(polychaeta), was surveyed by using fluorescent labelled lectins to elucidate their glycan-binding properties. Histochemical analyses showed the diversity of glycan patterns in the annelid. Mannose at the non-reducing terminus of glycans was found specifically at the periphery of the intestinal wall in addition to the whole tissue. The response of glycans with non-reducing terminal N-acetylglucosamine detected by Wheat germ agglutinin was weak on the tissue section. Contrastively, glycans with fucose detected by Ulex europaeus agglutinin-1 were present in limited parts of the notopodia. At the same time, Galβ1-3GalNAc/GlcNAc and β-galactoside appeared at the circular muscles surrounding the body and were detected by Agaricus bisporus agglutinin and Erythrina cristagalli agglutinin, respectively in the same region; NeuAcα2-6Gal/GalNAc glycan was detected by Sambucus sieboldiana agglutinin. However, NeuAcα2-3Gal/GalNAc was not present in the tissue of lugworm by Maackia amurensis agglutinin. These results indicated that β-galactoside glycans were expressed in the circular muscles of the polychaeta, with a partial presence of sialic acid. The glycoproteins in the annelid were isolated from the crude extract by lectin-conjugated agarose gels. The presence of glycoconjugates expressed in P. nuntia with characteristic glycan structures is a novel finding.
Edited by J.N. Govil, chapter Nutraceuticals and Functional Foods Volume 42, Chapter 18: pages 339-3
Recent Progress in Medicinal Plants
Lectins are a group of carbohydrate-binding proteins of non-immune origin found in a diversity of organisms, plants, animals, fungi, bacteria and virus with potent biological activity. The present chapter is an attempt to represent a multidisciplinary study on this lectins isolated from medicinal plants like Nymphaea nouchali, Kaempferia rotunda, Kaempferia parviflora, Alisma orientale, Pinellia ternate and Phthirusa pyrifolia covering their purification process, information on hemagglutination activities and inhibition by sugars, as well as variation of stability with the change of temperature, pH and in presence of denaturants. Along with the toxicity of Kaempferia rotunda lectin and Nymphaea nouchali lectin against the brine shrimp nauplii, antibacterial activities of Kaempferia rotunda lectin, Nymphaea nouchali lectin, Eugenia uniflora L seeds lectin and Phthirusa pyrifolia leaf lectin, antiproliferative activities of Alisma orientale lectin, Pinellia ternate lectin, Kaempferia rotunda lectin, Nymphaea nouchali lectin and Pinellia ternate agglutinin against a number of cancer cell lines are described in brief.
Fish Physiol Biochem 2014 Oct 27;40(5):1559-72. Epub 2014 May 27.
Division of Cell Recognition Study, Institute of Molecular Biomembrane and Glycobiology, Tohoku Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai, 981-8558, Japan,
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Molecules. 2014; 19(9): 13990-14003.
A specific galactose-binding lectin was shown to inhibit the hemolytic effect of streptolysin O (SLO), an exotoxin produced by Streptococcus pyogenes. Commercially available lectins that recognize N-acetyllactosamine (ECA), T-antigen (PNA), and Tn-antigen (ABA) agglutinated rabbit erythrocytes, but had no effect on SLO-induced hemolysis. In contrast, SLO-induced hemolysis was inhibited by AKL, a lectin purified from sea hare (Aplysia kurodai) eggs that recognizes α-galactoside oligosaccharides. This inhibitory effect was blocked by the co-presence of D-galactose, which binds to AKL. A possible explanation for these findings is that cholesterol-enriched microdomains containing glycosphingolipids in the erythrocyte membrane become occupied by tightly stacked lectin molecules, blocking the interaction between cholesterol and SLO that would otherwise result in penetration of the membrane. Growth of S. pyogenes was inhibited by lectins from a marine invertebrate (AKL) and a mushroom (ABA), but was promoted by a plant lectin (ECA). Both these inhibitory and promoting effects were blocked by co-presence of galactose in the culture medium. Our findings demonstrate the importance of glycans and lectins in regulating mechanisms of toxicity, creation of pores in the target cell membrane, and bacterial growth.
Fish Physiol. Biochem.Epub ahead of printing,DOI: 10.1007/s10695-014-9957-0
Fish Physiology and Biochemistry
Rhamnose-binding lectin (RBL) is one of the animal lectin categories which take part in the innate immune responses of fish. Osmerus lanceolatus lectin (OLL) from shishamo smelt eggs is an RBL composed of two tandem-repeated domains, both of which are considered to be a carbohydrate-recognition domain. SAL, catfish (Silurus asotus) egg RBL composed of three domains, binds to Burkitt’s lymphoma Raji cells through globotriaosylceramide (Gb3) carbohydrate chain and to reduce cell size and growth by altering membrane composition without causing cell death. In this experiment, we tried to compare the binding effects of these two RBLs on Raji cells. Flow cytometric and fluorescence microscopic analyses revealed that OLL also directly bound to and shrunk Raji cells with ten times less reactivity than SAL but reduced cell growth with decreasing cell viability. Anti-Gb3 antibody completely blocked the binding of SAL to Raji cells but not that of OLL. In addition, the direct bindings of OLL and SAL to Raji cells were comparably inhibited by melibiose, but lactose was more effective inhibitor for the binding of OLL than that of SAL. These results suggest that OLL has slightly different cell-binding property compared with SAL and binds not only to Gb3 but also to the other carbohydrate receptor-bearing β-galactoside chains. The quantitative RT-PCR analysis revealed that SAL induced the expression of TNF-α but not of IFN-γ, IL-1β, and IL-10. Thus, SAL-induced cytostatic effect on Raji cells might be partially caused by TNF-α-mediated signaling pathway.
Asian Pac J Trop Biomed. 2014 Apr 4(4): 306-311
Asian Pacific Journal of Tropical Biomedicine
Objective: To investigate and compare the resistance and sensitivity of Salmonella typhi samples to commonly used antibiotics in three major divisions of Bangladesh and to evaluate the gradually developing resistance pattern. Methods: The antibiotic susceptibility of 70 clinical isolates collected from blood, sputum, urine and pus samples were identified by specific antisera and with standard biochemical tests. The patients were divided into 5 age groups. Susceptibility and resistance was also tested by Kirby-Bauer disc diffusion method using 12 regularly used antibiotics. Results: Antibiotic susceptibility test demonstrated that 64.28% isolates of Salmonella typhi was multidrug resistant. Present study suggests that the clinical samples were mostly resistant against nalidixic acid with all age groups and in all three divisions with similar resistance pattern. Resistance is more common among adult people (30-40 years) and children (0-10 years). Salmonella typhi was mostly sensitive against gentamycin, chloramphenicol and ciprofloxacin. Conclusions: Although the population density of Dhaka region is markedly higher than Rajshahi and Chittagong regions, no significant difference in resistance pattern was found. The rate of multidrug resistance is a matter of concern. Physicians should reconsider before prescribing nalidixic acid and cefixime. Further molecular study is needed to reveal the genomic and proteomic basis of resistance.
Indian J Biochem. Biophys. 2014 Apr 51(2):142-148
Indian journal of biochemistry and biophysics
A new chitin-binding lectin was purified from a Bangladeshi cultivar ‘Deshi’ of potato (Solanum tuberosum L.) through anion-exchange and affinity chromatographies using a chitin column. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) showed the molecular mass of the lectin as 20,000 Daltons. This molecular mass was almost half of the molecular masses of chitin-binding lectins derived from other potatoes. The lectin showed both bactericidal and growth-inhibiting activities against Gram-positive (Listeria monocytogenes) and Gram-negative (Escherichia coli, Salmonella enteritidis and Shigella boydii) pathogenic bacteria. It also showed antifungal activity against Rhizopus spp., Penicillium spp. and Aspergillus niger. Biofilm produced by the bacterium Pseudomonas aeruginosa was dose-dependently reduced by 5-20% in 24 h after administration of the lectin, which was attributed to the glycan-binding property of the lectin having affinity to GlcNAc polymers. It was the first observation that any potato lectin prevented biofilm formation by P. aeruginosa and, therefore, could have possible applications in clinical microbiology and biomedical science.
Afr. J. Biotechnol. 2014 Apr;13(15):1679-1685
African Journal of Biotechnology
Cytotoxicity of tuber lectins from two potato cultivars was assessed and their anti-tumor potential against experimentally induced Ehrlich ascites carcinoma in Swiss albino mice was evaluated. Twenty (20) kDa chitin-binding lectins from Solanum tuberosum tubers, STL-S and STL-D were purified through ion-exchange and affinity chromatographic methods, hemagglutinating activity and blood group specificity of the lectins were checked whereas the cytotoxicity was determined using brine shrimp (Artemia salina L.) nauplii lethality assay. The lectins showed no specificity to animal and human erythrocytes. LC50 values for STL-S and STL-D were found to be 75 μg/ml and 90 μg/ml respectively with a dose-dependent intermediary toxic effect. After inducing ascites by intraperitoneal propagation, the Swiss albino mice were treated by administering the lectins at a dose of 1.38 mg/kg/day for 5 consecutive days. STL-S and STL-D showed 79.84% and 83.04% of growth inhibition of EAC cells respectively. Additionally, hemoglobin and RBC levels became considerably increased with a drop off in the WBC levels in the treated mice group indicating moderate anticancer activities exhibited by the potato lectins.
Glycoconjugate J. 2014 Feb 31(2):171-184
SBL/RC-RNase was originally isolated from frog (Rana catesbeiana) oocytes and purified as a novel sialic acid-binding lectin (SBL) that displayed strong anti-cancer activity. SBL was later shown to be identical to a ribonuclease (RC-RNase) from oocytes of the same species. The administration of SBL/RC-RNase induced apoptosis (with nuclear condensation and DNA fragmentation) in mouse leukemia P388 cells but did not kill umbilical vein endothelial or fibroblast cells derived from normal tissues. The cytotoxic activity of SBL/RC-RNase was inhibited by desialylation of P388 cells and/or the co-presence of free bovine submaxillary mucin. FACS analysis showed that SBL/RC-RNase was incorporated into cells after attachment to cholesterol-rich microdomains. Addition of the cholesterol remover methyl-β-cyclodextrin reduced SBL/RC-RNase-induced apoptosis. Apoptosis occurred through the caspase-3 pathway following activation of caspase-8 by SBL/RC-RNase. A heat shock cognate protein (Hsc70) and a heat shock protein (Hsp70) (each 70 kDa) on the cell membrane were shown to bind to SBL/RC-RNase by mass spectrometric and flow cytometric analyses. Quercetin, an inhibitor of Hsc70 and Hsp70, significantly reduced SBL/RC-RNase-induced apoptosis. Taken together, our findings suggest that sialyl-glycoconjugates present in cholesterol-rich microdomains form complexes with Hsc70 or Hsp70 that act as triggers for SBL/RC-RNase to induce apoptosis through a pathway involving the activation of caspase-3 and caspase-8.
Braz J Microbiol. 2013 May; 44(1): 97-103
Brazilian Journal of Microbiology
Forty-six bottled water samples representing 16 brands from Dhaka, Bangladesh were tested for the numbers of total coliforms, fecal indicator bacteria (i.e., thermotolerant Escherichia coli and Enterococcus spp.) and potential bacterial pathogens (i.e., Aeromonas hydrophila, Pseudomonas aeruginosa, Salmonella spp., and Shigella spp.). Among the 16 brands tested, 14 (86%), ten (63%) and seven (44%) were positive for total coliforms, E. coil and Enterococcus spp., respectively. Additionally, a further nine (56%), eight (50%), six (37%), and four (25%) brands were PCR positive for A. hydrophila lip, P. aeruginosa ETA, Salmonella spp. invA, and Shigella spp. ipaH genes, respectively. The numbers of bacterial pathogens in bottled water samples ranged from 28 ± 12 to 600 ± 45 (A. hydrophila lip gene), 180 ± 40 to 900 ± 200 (Salmonella spp. invA gene), 180 ± 40 to 1,300 ± 400 (P. aeruginosa ETA gene) genomic units per L of water. Shigella spp. ipaH gene was not quantifiable. Discrepancies were observed in terms of the occurrence of fecal indicators and bacterial pathogens. No correlations were observed between fecal indicators numbers and presence/absence of A. hydrophila lip (p = 0.245), Salmonella spp. invA (p = 0.433), Shigella spp. ipaH gene (p = 0.078), and P. aeruginosa ETA (p = 0.059) genes. Our results suggest that microbiological quality of bottled waters sold in Dhaka, Bangladesh is highly variable. To protect public health, stringent quality control is recommended for the bottled water industry in Bangladesh.
J. Biol. Chem. 2012 Dec 28; 287 (53): 44772-44783
Journal of Biological Chemistry
A novel lectin structure was found for a 17-kDa α-D-galactose-binding lectin (termed "MytiLec") isolated from the Mediterranean mussel, Mytilus galloprovincialis. The complete primary structure of the lectin was determined by Edman degradation and mass spectrometric analysis. MytiLec was found to consist of 149 amino acids with a total molecular mass of 16,812.59 Da by Fourier transform-ion cyclotron resonance mass spectrometry, in good agreement with the calculated value of 16,823.22 Da. MytiLec had an N terminus of acetylthreonine and a primary structure that was highly novel in comparison with those of all known lectins in the structure database. The polypeptide structure consisted of three tandem-repeat domains of ∼50 amino acids each having 45-52% homology with each other. Frontal affinity chromatography technology indicated that MytiLec bound specifically to globotriose (Gb3; Galα1-4Galβ1-4Glc), the epitope of globotriaosylceramide. MytiLec showed a dose-dependent cytotoxic effect on human Burkitt lymphoma Raji cells (which have high surface expression of Gb3) but had no such effect on erythroleukemia K562 cells (which do not express Gb3). The cytotoxic effect of MytiLec was specifically blocked by the co-presence of an α-galactoside. MytiLec treatment of Raji cells caused increased binding of anti-annexin V antibody and incorporation of propidium iodide, which are indicators of cell membrane inversion and perforation. MytiLec is the first reported lectin having a primary structure with the highly novel triple tandem-repeat domain and showing transduction of apoptotic signaling against Burkitt lymphoma cells by interaction with a glycosphingolipid-enriched microdomain containing Gb3.
Toxins. 2012 April 30; 4 (5): 323-338
A divalent cation-independent lectin-HOL-18, with cytotoxic activity against leukemia cells, was purified from a demosponge, Halichondria okadai. HOL-18 is a 72 kDa tetrameric lectin that consists of four non-covalently bonded 18 kDa subunits. Hemagglutination activity of the lectin was strongly inhibited by chitotriose (GlcNAcβ1-4GlcNAcβ1-4GlcNAc), fetuin and mucins from porcine stomach and bovine submaxillary gland. Lectin activity was stable at pH 4-12 and temperatures lower than 60 °C. Frontal affinity chromatography with 16 types of pyridylaminated oligosaccharides indicated that the lectin had an affinity for N-linked complex-type and sphingolipid-type oligosaccharides with N-acetylated hexosamines and neuramic acid at the non-reducing termini. The lectin killed Jurkat leukemia T cells and K562 erythroleukemia cells in a dose- and carbohydrate-dependent manner.
Biosci. Rep. 2011 Dec; 31 (6): 465-475
A lectin (termed NNTL) was purified from the extracts of Nymphaea nouchali tuber followed by anion-exchange chromatography on DEAE-cellulose, hydrophobic chromatography on HiTrap Phenyl HP and by repeated anion-exchange chromatography on HiTrap Q FF column. The molecular mass of the purified lectin was 27.0 ± 1.0 kDa, as estimated by SDS/PAGE both in the presence and in the absence of 2-mercaptoethanol. NNTL was an o-nitrophenyl β-D-galactopyranoside sugar-specific lectin that agglutinated rat, chicken and different groups of human blood cells and exhibited high agglutination activity over the pH range 5-9 and temperatures of 30-60 °C. The N-terminal sequence of NNTL did not show sequence similarity with any other lectin and the amino acid analysis revealed that NNTL was rich in leucine, methionine and glycine residues. NNTL was a glycoprotein containing 8% neutral sugar and showed toxicity against brine shrimp nauplii with an LC(50) value of 120 ± 29 μg/ml and exerted strong agglutination activity against four pathogenic bacteria (Bacillus subtilis, Sarcina lutea, Shigella shiga and Shigella sonnei). In addition, antiproliferative activity of this lectin against EAC (Ehrlich ascites carcinoma) cells showed 56% and 76% inhibition in vivo in mice at 1.5 and 3 mg·kg(-1)·day(-1) respectively. NNTL was a divalent ion-dependent glycoprotein, which lost its activity markedly in the presence of denaturants. Furthermore, measurement of fluorescence spectra in the presence and absence of urea and CaCl(2) indicated the requirement of Ca(2+) for the stability of NNTL.
Malaysian J Microbiol. 2011 Jan; 7(2): 92-96
Malaysian Journal of Microbiology
Chitinases (designated as SPCs) were isolated from ‘Shilbilati’ potatoes, a potato prototype cultivated in Bangladesh by affinity chromatography on a chitin column. SPCs agglutinated rat erythrocytes at the minimum concentration of 7 µg/mL and showed toxicity against brine shrimp nauplii with the LC50 value of 20 µg/mL. The chitinases also agglutinated seven bacterial strains among the twelve as studied. Pseudomonas aeruginosa, Bacillus subtilis and Salmonella typhi were the most sensitive towards the SPCs and were agglutinated at 1.2, 2.5 and 5.0 µg/mL protein concentrations respectively. Antibacterial tests demonstrated that SPCs showed inhibitory activity against the pathogenic bacteria Staphylococcus aureus, Bacillus subtilis and Salmonella typhi. Antifungal activity was investigated by the disc diffusion method. Five fungal species (Candida albicans, Aspergillus niger, Fusarium vasinfectum, Aspergillus fumigatus and Aspergillus flavus) and two fungal genus (Penicillium and Mucor sp.) were examined in the assay. SPCs showed antifungal activity against Candida albicans, Fusarium vasinfectum and Penicillium sp.
Can. J. Microbiol. 2010 Sep 27: 56 (10): 838-845
Canadian Journal of Microbiology
This paper aimed to assess the magnitude of sewage pollution in an urban lake in Dhaka, Bangladesh, by using quantitative PCR of sewage-associated Bacteroides HF183 markers. PCR was also used for the quantitative detection of ruminant wastewater-associated CF128 markers along with the enumeration of traditional fecal indicator bacteria, namely enterococci. The number of enterococci in lake water samples ranged from 1.1 × 10⁴ to 1.9 × 10⁵ colony-forming units/100 mL water. From the 20 water samples tested, 14 (70%) and 7 (35%) were PCR positive for HF183 and CF128 markers, respectively. The numbers of HF183 and CF128 markers in lake water samples were 3.9 × 10⁴ to 6.3 × 10⁷ and 9.3 × 10³ to 6.3 × 10⁵ genomic units/100 mL water, respectively. The high numbers of enterococci and HF183 markers are indicative of sewage pollution and potential health risks to those who use the lake water for nonpotable purposes such as bathing and washing clothes. This is the first study that investigated the presence of microbial source tracking markers in Dhaka, Bangladesh, where diarrhoeal disease is one of the major causes of childhood mortality. The molecular assay used in this study can provide valuable information on the extent of sewage pollution, thus facilitating the development of robust strategies to minimize potential health risks.
World J. Zool. 2010 Jun; 5 (2): 110-114
World Journal of Zoology
Rotifer is the most dominant zooplankton in all the freshwater aquatic ecosystems and considered as ideal food for fish larvae. High density culture of Brachionus calyciflorus, one of the most common rotifer species, was conducted in laboratory condition. Starting from the step of isolation and inoculation to production and preservation of resting eggs were successfully carried out by simplification and adaptation of existing high density culture method to local ingredients and environment. Fresh algae- Phacus, algae paste, Baker’s yeast and mushroom powder was provided as feed in the B. calyciflorus culture vessel of 100L glass tanks 4 times daily. Nutritional Enrichment of the target species was carried out by egg yolk and cod liver oil. Present study reveals that embryonic development of B. calyciflorus requires 0.5 days, female attains reproductive maturity after 1-1.2 days, Interval period between two spawning was 3.5-3.8 hours and the doubling time was 2.26 days. The average final density during this culture was obtained 685 ± 35 individual.ml-1 while the maximum was 721 individual.ml-1. Resting eggs were enumerated 1800/mg. The study also found that as the density of rotifer increases the ratio of egg production decreases but also the rate of growth per day continues to increase.
World J. Fish Marine Sci. 2010 2 (1): 37-39
World Journal of Fish and Marine Science
Larval rearing of Labeo rohita were carried out under different stocking density and diet including live food. Micro-algae Spirulina, Phacus and Brachionus calyciflorus were used as live food. The rotifer was nutritionally enriched before introducing to larval culture system. Larvae of Labeo rohita were experimentally stocked in three density levels for three types of diet. The low, medium and high stocking densities were respectively 15, 30 and 45 individuals.10L-1. Three diet types were traditional, single live food (Brachionus calyciflorus) and mixed live food (Spirulina & Brachionus calyciflorus). The maximum survival (91%), average length attainment (3.28 mm/day) and weight gain (3.94 mg/day) were observed at low density- mixed live food system. The growth performance in mixed live food was around 2.5 fold higher than traditional method and approximately 1.45 fold higher than single live food diet. While single live food diet showed about 1.8 fold higher growth than traditional method. The larvae of Labeo rohita responded best with mixed diet including phytoplankton (Spirulina) and rotifer (Brachionus calyciflorus).
J. Sci. Res. 2010 Jan; 2 (2): 390-396
Journal of Scientific Research
This proximate study was carried out to determine the nutrient content of six commercially important molluscs. The selected molluscan species were Pila globosa, Bellamya bengalensis, Melania tuberculata, Lamellidens marginalis, Anisus convexiusculus and Helix sp. These species were assessed for their proximate and mineral compositions designed to establish their nutritive values on the wet weight basis. The analysis of muscles revealed that the composition of crude protein varied from 8.272%±0.05% in Pila globosa to 12.927%±0.57% in Anisus convexiusculus, moisture content varied from 74.6%±0.04% in Melania tuberculata to 85.9%±0.68% in Lamellidens marginalis and in case of ash content it varied from 1.036%±0.02% in Pila globosa to 4.607%±0.01% in Anisus convexiusculus. Carbohydrate content varied from 2.902±0.03% in Pila globosa and 7.566%±0.37% in Melania tuberculata. The fat and crude fiber content was marginally small in all of the species. The concentrations of calcium, phosphorus, iron, sodium and potassium in the flesh and shells of the molluscs were determined. It becomes pretty clear that molluscs are excellent sources of some required trace and minor elements needed for the proper growth and development of human being and can also be used as high-nutrient supplementary feed for domestic animals, birds and even for fish culture.
Global J. Env. Res. 2009 Sep;3 (3): 218-222
Global Journal of Environmental Research
Water of Buriganga River, beside Dhaka and of a rural river Panguchi was studied and compared for pollution by determining various water quality parameters for one year. The river Buriganga is subjected to severe pollution whereas Panguchi is considered a less polluted river. The pH range is 6.69 to 8.14 for the river Buriganga and 6.90 to 8.80 for the river Panguchi. The organic pollution in river Buriganga is much more severe as indicated by DO (4.22 to 6.84) and BOD (0.97 to 3.12) than river Panguchi as the values are 7.16 to 8.66 and 5.43 to 5.73 respectively. The overall study shows that the degree of river pollution is quite alarming for the urban population.
J. Bio-sci. 2009 Jan; 17: 35-40
Journal of Bio-science
Context: Hilsha is one of the most popular fish in Bangladesh. Biochemical analysis of Hilsha egg revealed that it is quite a healthful food. A specific class of proteins called lectins is partially purified from this source. Objectives: To carry the nutritional analysis of Hilsha eggs and to isolate sugar-specific lectins from the animal source by applying effective purification techniques. Materials and Methods: The moisture, ash, protein, lipid, polysaccharide, free sugar, cholesterol, calcium, phosphorus and iron contents were determined by the conventional methods and the lectins were isolated by using the affinity chromatographic technique. The effect of temperature, pH and metal ions were observed by performing the hemagglutination assay. Results: The moisture, ash, protein, lipid, polysaccharide, free sugar, cholesterol, calcium, phosphorus and iron contents were 34-, 2.4-, 32.59-, 28.35-, 0.036-, 0.059-, 0.40-, 0.178-, 0.193- and 0.136%, respectively. The partially purified crude protein by affinity chromatography from Hilsha eggs agglutinated rabbit erythrocytes and the hemagglutinating activity is inhibited by 25mM Raffinose followed by 100 mM of glucose, N-acetyl-D-glucosamine, N-acetyl-D-galactosamine and D-galactosamine-HCl each. In the presence of the chelating agent EDTA, the lectin lost its activity completely. Thermal and pH inactivation assay of the lectin indicates that the activity is highest at 30 to 40°C and at the pH 5 to 9, respectively. Conclusion: Hilsha fish eggs can be recommended as a nutritious food and as well as can be regarded as a source of animal lectins, a group of sugar-binding proteins.