title: Bactericidal activity of fish galectin 4 derived membrane-binding peptide tagged with oligotryptophan.
abstract: Galectins belong to the family of galactoside-binding proteins which act as pathogen recognition receptors by recognizing and binding to the carbohydrate present in the bacterial membranes. In this study, a Galectin-4 sequence was identified from the constructed cDNA library of Channa striatus and its structural features were reported. Gene expression analysis revealed that CsGal4 was highly expressed in liver and strongly induced by Epizootic Ulcerative Syndrome (EUS) causing pathogens such as Aphanomyces invadans, Aeromonas hydrophila and a viral analogue, poly I:C. To understand the antimicrobial role of putative dimerization site of CsGal4, the region was chemically synthesized and its bactericidal effect was determined. G4 peptide exhibited a weak bactericidal activity against Vibrio harveyi, an important aquaculture pathogen. We have also determined the bactericidal activity of the dimerization site by tagging pentamer oligotryptophan (W5) at the C-terminal of G4 peptide. Flow cytometry analysis revealed that G4W induced drastic reduction in cell counts than G4. Electron microscopic images showed membrane blebbings in V. harveyi which indicated the membrane disrupting activity of G4W. Interestingly, both the peptides did not exhibit any hemolytic activity and cytotoxicity towards peripheral blood cells of Channa striatus and the activity was specific only towards the bacterial membrane. Our results suggested that addition of W5 at the C-terminal of membrane-binding peptide remarkably improved its membrane disrupting activity.
authors.affiliation: Division of Fisheries Biotechnology & Molecular Biology, Department of Biotechnology, Faculty of Science and Humanities, SRM University, Kattankulathur 603 203, Chennai, Tamil Nadu, India; Department of Microbiology, SRM Arts & Science College, Kattankulathur 603 203, Chennai, India.
authors.forename: Abirami
authors.initials: A
authors.lastname: Arasu
authors.affiliation: Division of Fisheries Biotechnology & Molecular Biology, Department of Biotechnology, Faculty of Science and Humanities, SRM University, Kattankulathur 603 203, Chennai, Tamil Nadu, India.
authors.forename: Venkatesh
authors.initials: V
authors.lastname: Kumaresan
authors.affiliation: Interdisciplinary Institute of Indian System of Medicine (IIISM), SRM University, Kattankulathur 603 203, Chennai, Tamil Nadu, India.
authors.forename: Munuswamy-Ramanujam
authors.initials: MR
authors.lastname: Ganesh
authors.affiliation: Lab PCN 206, Microbiology Division, CSIR-Central Drug Research Institute, B.S. 10/1, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow-226031, Uttar Pradesh, India.
authors.forename: Mukesh
authors.initials: M
authors.lastname: Pasupuleti
authors.affiliation: Department of Botany and Microbiology, Addiriyah Chair for Environmental Studies, College of Science, King Saud University, P. O. Box 2455, Riyadh 11451, Saudi Arabia.
authors.forename: Mariadhas Valan
authors.initials: MV
authors.lastname: Arasu
authors.affiliation: Department of Botany and Microbiology, Addiriyah Chair for Environmental Studies, College of Science, King Saud University, P. O. Box 2455, Riyadh 11451, Saudi Arabia.
authors.forename: Naif Abdullah
authors.initials: NA
authors.lastname: Al-Dhabi
authors.affiliation: Division of Fisheries Biotechnology & Molecular Biology, Department of Biotechnology, Faculty of Science and Humanities, SRM University, Kattankulathur 603 203, Chennai, Tamil Nadu, India. Electronic address: jesuaraj@hotmail.com.
authors.forename: Jesu
authors.initials: J
authors.lastname: Arockiaraj
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D044744:Aphanomyces / Q000276:immunology*; D017756:Aquaculture; D001433:Bacteriolysis; D002478:Cells, Cultured; D003001:Cloning, Molecular; D019281:Dimerization; D005393:Fish Diseases / Q000276:immunology* / Q000628:therapy; D029941:Fish Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D037541:Galectin 4 / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D015870:Gene Expression; D005818:Genetic Engineering; D010455:Peptides / Q000138:chemical synthesis / Q000235:genetics / Q000627:therapeutic use*; D010473:Perciformes / Q000276:immunology*; D014364:Tryptophan / Q000138:chemical synthesis; D014735:Vibrio Infections / Q000276:immunology* / Q000628:therapy
chemical_list: D000900:Anti-Bacterial Agents; D029941:Fish Proteins; D037541:Galectin 4; D010455:Peptides; D014364:Tryptophan
keywords: Carbohydrate recognition domain; Galectin; Membrane binding; Oligotryptophan tagging; Peptide