Influence on the plasma membrane of Candida albicans by HP (2–9)–magainin 2 (1–12) hybrid peptide

Abstract

A 20-residue hybrid peptide (HP (2–9)–MA (1–12): HP–MA), incorporating 2–9 residues of Helicobacter pyroli ribosomal protein L1 (HP) and 1–12 residues of magainin 2 (MA), has more potent antibacterial activity than parent peptide HP (2–20) and magainin 2. In this study, the antifungal activity and its mechanism of HP–MA were investigated. HP–MA displayed a strong antifungal activity in an energy-dependent manner. To elucidate the antifungal mechanism(s) of HP–MA, FACScan analysis and the change in membrane dynamics using 1,6-diphenyl-1,3,5-hexatriene (DPH) as a membrane probe of Candida albicans were examined. The results indicated that the HP–MA exerts its antifungal effect by acting on the plasma membrane. Furthermore, the peptide induced remarkable morphological change when tested for membrane disrupting activity using liposomes (PC/Cholesterol; 10:1, w/w). In C. albicans, dimorphism plays a crucial role in pathogenesis but HP–MA could disrupt the mycelial forms and exert its antifungal effect on the blastoconidia in 20% fetal bovine serum.