Fungicidal effect and the mode of action of piscidin 2 derived from hybrid striped bass.
Piscidin 2 (P2), a 22-residue cationic peptide isolated from the mast cells of hybrid striped bass, has potent antibacterial activities. However, its antifungal properties are not completely understood. In the current study, we investigated the antifungal effects and mode of action of P2. P2 exhibited potent antifungal activity against human pathogenic fungi. To understand the fungicidal properties of P2, we focused on a membrane-active mechanism of the peptide by in vivo and in vitro testing. Flow cytometric analysis using bis-(1,3-dibutylbarbituric acid) trimethine oxonol [DiBAC(4)(3)] and protoplast regeneration experiments showed that P2 caused fungal membrane damage. Furthermore, fluorescence analysis using 1,6-diphenyl-1,3,5-hexatriene (DPH) revealed that P2 created pores in fungal membranes. These results were confirmed with dye leakage tests by using liposomes composed of phosphatidylcholine/phosphatidylserine (3:1, w/w), which mimicked fungal membranes. The present study indicated that P2 exerts its fungicidal effects by perturbing membrane activities.
Sung
Woo Sang
WS
School of Life Sciences & Biotechnology, College of Natural Sciences, Kyungpook National University, 1370 Sankyuk-dong, Puk-ku, Daegu 702-701, Republic of Korea.
Lee
Juneyoung
J
Lee
Dong Gun
DG
D000595:Amino Acid Sequence; D000935:Antifungal Agents / Q000737:chemistry / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry / Q000494:pharmacology*; D001463:Barbiturates / Q000032:analysis; D002176:Candida albicans / Q000187:drug effects*; D002462:Cell Membrane / Q000187:drug effects*; D004161:Diphenylhexatriene / Q000032:analysis; D029941:Fish Proteins / Q000737:chemistry / Q000494:pharmacology*; D005434:Flow Cytometry; D005456:Fluorescent Dyes / Q000032:analysis; D006801:Humans; D007555:Isoxazoles / Q000032:analysis; D008290:Malassezia / Q000187:drug effects*; D008564:Membrane Potentials / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D014250:Trichosporon / Q000187:drug effects*
D000935:Antifungal Agents; D023181:Antimicrobial Cationic Peptides; D001463:Barbiturates; D029941:Fish Proteins; D005456:Fluorescent Dyes; D007555:Isoxazoles; C449802:moronecidin protein, Morone saxatilis; C052795:bis(1,3-dibutylbarbiturate)trimethine oxonol; D004161:Diphenylhexatriene