title: Antifungal mechanism of an antimicrobial peptide, HP (2--20), derived from N-terminus of Helicobacter pylori ribosomal protein L1 against Candida albicans.
abstract: The antifungal activity and mechanism of HP (2-20), a peptide derived from the N-terminus sequence of Helicobacter pylori Ribosomal Protein L1 were investigated. HP (2--20) displayed a strong antifungal activity against various fungi, and the antifungal activity was inhibited by Ca(2+) and Mg(2+) ions. In order to investigate the antifungal mechanism(s) of HP (2-20), fluorescence activated flow cytometry was performed. As determined by propidium iodide staining, Candida albicans treated with HP (2-20) showed a higher fluorescence intensity than untreated cells and was similar to melittin-treated cells. The effect on fungal cell membranes was examined by investigating the change in membrane dynamics of C. albicans using 1,6-diphenyl-1,3,5-hexatriene as a membrane probe and by testing the membrane disrupting activity using liposome (PC/PS; 3:1, w/w) and by treating protoplasts of C. albicans with the peptide. The action of peptide against fungal cell membrane was further examined by the potassium-release test, and HP (2-20) was able to increase the amount of K(+) released from the cells. The result suggests that HP (2-20) may exert its antifungal activity by disrupting the structure of cell membrane via pore formation or directly interacts with the lipid bilayers in a salt-dependent manner.
authors.affiliation: Research Center for Proteineous Materials, Chosun University, 375 Seosuk-Dong, Dong-Ku, Kwangju 501-759, Korea.
authors.forename: Dong Gun
authors.initials: DG
authors.lastname: Lee
authors.forename: Yoonkyung
authors.initials: Y
authors.lastname: Park
authors.forename: Hee Nam
authors.initials: HN
authors.lastname: Kim
authors.forename: Hyung Keun
authors.initials: HK
authors.lastname: Kim
authors.forename: Pyoung Il
authors.initials: PI
authors.lastname: Kim
authors.forename: Bo Hwa
authors.initials: BH
authors.lastname: Choi
authors.forename: Kyung-Soo
authors.initials: KS
authors.lastname: Hahm
mesh_terms: D000935:Antifungal Agents / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D002118:Calcium / Q000494:pharmacology; D002176:Candida albicans / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D002462:Cell Membrane / Q000187:drug effects; D002473:Cell Wall / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D005434:Flow Cytometry; D016480:Helicobacter pylori; D007700:Kinetics; D008081:Liposomes / Q000032:analysis; D008274:Magnesium / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D010446:Peptide Fragments / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D011188:Potassium / Q000378:metabolism; D011523:Protoplasts / Q000187:drug effects / Q000502:physiology; D012038:Regeneration; D012269:Ribosomal Proteins / Q000737:chemistry
chemical_list: D000935:Antifungal Agents; D001426:Bacterial Proteins; C433783:Hp (2-20) protein, Helicobacter pylori; D008081:Liposomes; D010446:Peptide Fragments; D012269:Ribosomal Proteins; C028546:ribosomal protein L1; D008274:Magnesium; D011188:Potassium; D002118:Calcium