Antimicrobial Peptide CGA-N12 Decreases the Candida tropicalis Mitochondrial Membrane Potential via Mitochondrial Permeability Transition Pore.

CGA-N12 is an antimicrobial peptide derived from the N-terminus of human chromogranin A and comprises the 65th to the 76th amino acids. Our previous studies showed that CGA-N12 reduces Candida tropicalis mitochondrial membrane potential. Here, we explored the mechanism that CGA-N12 collapsed the mitochondrial membrane potential by investigations of its action on the mitochondrial permeability transition pore (mPTP) complex of C. tropicalis. The results showed that CGA-N12 induced Cyt c leakage, mitochondria swelling and led to PEG of molecular weight 1000 Da penetrate mitochondria. mPTP opening inhibitors bongkrekic acid (BA) could contract the mitochondrial swelling induced by CGA-N12, but CsA could not. Therefore, we speculated that CGA-N12 could induced C. tropicolis mPTP opening by preventing the matrix-facing (m) conformation of adenine nucleotide transporter (ANT), thereby increasing the permeability of the mitochondrial membrane and resulted in the mitochondrial potential dissipation.