title: Identification and characterisation of a novel antimicrobial polypeptide from the skin secretion of a Chinese frog (Rana chensinensis).
abstract: Amphibians secrete small antimicrobial polypeptides from their skin that have been explored as alternatives to conventional antibiotics. In this study, mass spectrometry was used to identify and characterise protein secretions from the skin of a Chinese frog, Rana chensinensis. The skin of this kind of frog has been used in traditional Chinese medicine for centuries as a remedy against inflammation. A novel antimicrobial peptide was identified and the characteristics of this peptide were analysed using far-ultraviolet circular dichroism. When dissolved in aqueous solution, the peptide displayed a high level of random coil structure, in contrast to a more ordered alpha-helical structure when dissolved in 50% trifluoroethanol. Functional studies showed that this peptide has potent antimicrobial activity both against Gram-positive and Gram-negative bacteria and has extremely low haemolytic activity to human red blood cells. Taken together, these studies suggest that this novel peptide can be further developed as an antimicrobial agent.
authors.affiliation: School of Life Sciences, Liaoning University, 66 Chong Shan Zhong Lu Road, Shen Yang 110036, PR China.
authors.forename: Li L
authors.initials: LL
authors.lastname: Jin
authors.forename: Shu S
authors.initials: SS
authors.lastname: Song
authors.forename: Qiang
authors.initials: Q
authors.lastname: Li
authors.forename: Yu H
authors.initials: YH
authors.lastname: Chen
authors.forename: Qiu Y
authors.initials: QY
authors.lastname: Wang
authors.forename: Sheng T
authors.initials: ST
authors.lastname: Hou
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology* / Q000633:toxicity; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology* / Q000633:toxicity; D012634:Bodily Secretions / Q000737:chemistry*; D002942:Circular Dichroism; D004912:Erythrocytes / Q000187:drug effects; D006090:Gram-Negative Bacteria / Q000187:drug effects*; D006094:Gram-Positive Bacteria / Q000187:drug effects*; D006801:Humans; D011487:Protein Conformation; D011898:Ranidae; D012867:Skin / Q000737:chemistry*; D013053:Spectrophotometry
chemical_list: D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides