Fungicidal effect of indolicidin and its interaction with phospholipid membranes.
The fungicidal effect and mechanism of a tryptophan-rich 13-mer peptide, indolicidin derived from granules of bovine neutrophils, were investigated. Indolicidin displayed a strong fungicidal activity against various fungi. In order to understand the fungicidal mechanism(s) of indolicidin, we examined the interaction of indolicidin with the pathogenic fungus Trichosporon beigelii. Fluorescence confocal microscopy and flow cytometry analysis revealed that indolicidin acted rapidly on the plasma membrane of the fungal cells in an energy-independent manner. This interaction is also dependent on the ionic environment. Furthermore, indolicidin caused significant morphological changes when tested for the membrane disrupting activity using liposomes (phosphatidylcholine/cholesterol; 10:1, w/w). The results suggest that indolicidin may exert its fungicidal activity by disrupting the structure of cell membranes, via direct interaction with the lipid bilayers, in a salt-dependent and energy-independent manner.
Lee
Dong Gun
DG
School of Life Science and Biotechnology, College of Natural Sciences, Kyungpook National University, 1370 Sankyuk-dong, Puk-ku, 702-701, Taegu, Republic of Korea. kshahm@mail.chosun.ac.kr
Kim
Hyung Keun
HK
Kim
Sun Am
SA
Park
Yoonkyung
Y
Park
Seong-Cheol
SC
Jang
Seung-Hwan
SH
Hahm
Kyung-Soo
KS
D000595:Amino Acid Sequence; D000935:Antifungal Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D002462:Cell Membrane / Q000187:drug effects / Q000648:ultrastructure; D002463:Cell Membrane Permeability / Q000187:drug effects; D002784:Cholesterol; D005434:Flow Cytometry; D008081:Liposomes / Q000737:chemistry; D018613:Microscopy, Confocal; D008969:Molecular Sequence Data; D010713:Phosphatidylcholines; D010743:Phospholipids / Q000378:metabolism*; D012492:Salts / Q000494:pharmacology; D014250:Trichosporon / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure
D000935:Antifungal Agents; D023181:Antimicrobial Cationic Peptides; D008081:Liposomes; D010713:Phosphatidylcholines; D010743:Phospholipids; D012492:Salts; C073143:indolicidin; D002784:Cholesterol