title: Applications of circular dichroism for structural analysis of gelatin and antimicrobial peptides.
abstract: Circular dichroism (CD) is a useful technique for monitoring changes in the conformation of antimicrobial peptides or gelatin. In this study, interactions between cationic peptides and gelatin were observed without affecting the triple helical content of the gelatin, which was more strongly affected by anionic surfactant. The peptides did not adopt a secondary structure in the presence of aqueous solution or Tween 80, but a peptide secondary structure formed upon the addition of sodium dodecyl sulfate (SDS). The peptides bound to the phosphate group of lipopolysaccharide (LPS) and displayed an alpha-helical conformation while (KW)(4) adopted a folded conformation. Further, the peptides did not specifically interact with the fungal cell wall components of mannan or laminarin. Tryptophan blue shift assay indicated that these peptides interacted with SDS, LPS, and gelatin but not with Tween 80, mannan, or laminarin. The peptides also displayed antibacterial activity against P. aeruginosa without cytotoxicity against HaCaT cells at MIC, except for HPA3NT3-analog peptide. In this study, we used a CD spectroscopic method to demonstrate the feasibility of peptide characterization in numerous environments. The CD method can thus be used as a screening method of gelatin-peptide interactions for use in wound healing applications.
authors.affiliation: Research Center for Proteineous Materials, Chosun University, Gwangju 501-759, Korea.
authors.forename: Ramamourthy
authors.initials: R
authors.lastname: Gopal
authors.affiliation: Department of Biotechnology, Chosun University, Gwangju 501-759, Korea.
authors.forename: Jin Soon
authors.initials: JS
authors.lastname: Park
authors.affiliation: Department of Bioinformatics, Kongju National University, Kongju, South Korea.
authors.forename: Chang Ho
authors.initials: CH
authors.lastname: Seo
authors.affiliation: Department of Biotechnology, Chosun University, Gwangju 501-759, Korea.
authors.forename: Yoonkyung
authors.initials: Y
authors.lastname: Park
mesh_terms: D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000737:chemistry; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry* / Q000633:toxicity; D002460:Cell Line; D002473:Cell Wall / Q000737:chemistry; D002942:Circular Dichroism / Q000379:methods*; D005780:Gelatin / Q000737:chemistry*; D005936:Glucans / Q000737:chemistry; D006801:Humans; D008070:Lipopolysaccharides / Q000737:chemistry; D008351:Mannans / Q000737:chemistry; D008969:Molecular Sequence Data; D011136:Polysorbates; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D012967:Sodium Dodecyl Sulfate; D013050:Spectrometry, Fluorescence; D013501:Surface-Active Agents; D014364:Tryptophan / Q000737:chemistry
chemical_list: D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; D005936:Glucans; D008070:Lipopolysaccharides; D008351:Mannans; D011136:Polysorbates; D013501:Surface-Active Agents; D012967:Sodium Dodecyl Sulfate; D014364:Tryptophan; D005780:Gelatin; C008247:laminaran