Internalization and membrane activity of the antimicrobial peptide CGA-N12.
Antimicrobial peptides (AMPs) are conventional antibiotic alternatives due to their broad-spectrum antimicrobial activities and special mechanisms of action against pathogens. The antifungal peptide CGA-N12 was originally derived from human chromogranin A (CGA) and consists of the 65th to 76th amino acids of the CGA N-terminal region. In the present study, we found that CGA-N12 had fungicidal activity and exhibited time-dependent inhibition activity against Candida tropicalis. CGA-N12 entered the cells to exert its antagonist activity. The internalization of CGA-N12 was energy-dependent and accompanied by actin cytoskeleton-, clathrin-, sulfate proteoglycan-, endosome-, and lipid-depleting agent-mediated endocytosis. Moreover, the CGA-N12 internalization pathway was related to the peptide concentration. The effects of CGA-N12 on the cell membrane were investigated. CGA-N12 at a low concentration less than 4 × MIC100 did not destroy the cell membrane. While with increasing concentration, the damage to the cell membrane caused by CGA-N12 became more serious. At concentrations greater than 4 × MIC100, CGA-N12 destroyed the cell membrane integrity. Therefore, the membrane activity of CGA-N12 is concentration dependant.
['Li|Ruifang|R|0000-0002-4824-0930', 'Tao|Mengke|M|', 'Li|Shang|S|', 'Wang|Xueqin|X|', 'Yang|Yanhui|Y|', 'Mo|Lianfeng|L|', 'Zhang|Kaidi|K|', 'Wei|Ao|A|', 'Huang|Liang|L|']
D000935:Antifungal Agents D001692:Biological Transport D002118:Calcium D041022:Candida tropicalis D002462:Cell Membrane D053379:Chromogranin A D004705:Endocytosis D006801:Humans D052899:Pore Forming Cytotoxic Proteins
internalization membrane activity CGA-N12 antifungal peptide endocytosis pathway