Fungicidal effect of antimicrobial peptide, PMAP-23, isolated from porcinemyeloid against Candida albicans

The antifungal activity and mechanism of a 23-mer peptide, PMAP-23, derived from pig myeloid was investigated. PMAP-23 displayed strong antifungal act ivity against yeast and mold. To investigate the antifungal mechanism of PM AP-23, fluorescence activated flow cytometry and confocal laser scanning mi croscopy were performed. Candida albicans treated with PMAP-23 showed highe r fluorescence intensity by propidium iodide(PI) staining, which was simila r to that of Melittin than untreated cells. Confocal microscopy showed that the peptide was located in the plasma membrane. The action of peptides aga inst fungal cell membranes was examined by treating prepared protoplasts of C. albicans with the peptide and lipid vesicle titration test. The result showed that the peptide prevented the regeneration of fungal cell walls and induced release of the fluorescent dye trapped in the artificial membrane vesicles, indicating that the peptide exerts its antifungal activity by act ing on the plasma lipid membrane. (C) 2001 Academic Press.