title: Mechanism of antifungal activity of antimicrobial peptide APP, a cell-penetrating peptide derivative, against Candida albicans: intracellular DNA binding and cell cycle arrest.
abstract: We investigated the antifungal properties and anti-candidal mechanism of antimicrobial peptide APP. The minimum inhibitory concentration of APP was 8 μM against Candida albicans and Aspeogillus flavus, the concentration against Saccharomyces cerevisiae and Cryptococcus neoformans was 16 μM, while 32 μM inhibited Aspergilla niger and Trichopyton rubrum. APP caused slight depolarization (12.32 ± 0.87%) of the membrane potential of intact C. albicans cells when it exerted its anti-candidal activity and only caused 21.52 ± 0.48% C. albicans cell membrane damage. APP interacted with cell wall membrane, caused potassium efflux and nucleotide leakage. However, confocal fluorescence microscopy experiment and flow cytometry confirmed that FITC-labeled APP penetrated C. albicans cell membrane with 52.31 ± 1.88% cell-penetrating efficiency and accumulated in the cytoplasm. Then, APP interact with C. albicans genomic DNA and completely suppressed DNA migration above weight ratio (peptide/DNA) of 2, and significantly arrested cell cycles during the S-phase (S-phase cell population was 27.09 ± 0.73%, p < 0.05) after penetrating the cell membrane. Results indicated that APP kills C. albicans for efficient cell-penetrating efficiency, strong DNA-binding affinity and significant physiological changes inducing S-phase arrest in intracellular environment.
authors.affiliation: Institute of Food Nutrition and Safety, School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu Province, China. lilirong-lily@126.com.|Yunnan Institute of Food Safety, Kunming University of Science and Technology, Kunming, Yunnan Province, China. lilirong-lily@126.com.
authors.forename: Lirong
authors.initials: L
authors.lastname: Li
authors.affiliation: Institute of Food Nutrition and Safety, School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu Province, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Sun
authors.affiliation: Institute of Food Nutrition and Safety, School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu Province, China.
authors.forename: Shufang
authors.initials: S
authors.lastname: Xia
authors.affiliation: Institute of Food Nutrition and Safety, School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu Province, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Tian
authors.affiliation: Human Nutrition Department, Egerton University, PO BOX 536, Egerton, Kenya.
authors.forename: Maureen Jepkorir
authors.initials: MJ
authors.lastname: Cheserek
authors.affiliation: Institute of Food Nutrition and Safety, School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu Province, China. lgw@jiangnan.edu.cn.
authors.forename: Guowei
authors.initials: G
authors.lastname: Le
mesh_terms: D000595:Amino Acid Sequence; D000935:Antifungal Agents / Q000138:chemical synthesis / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides / Q000138:chemical synthesis / Q000494:pharmacology*; D001230:Aspergillus / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D002176:Candida albicans / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002463:Cell Membrane Permeability; D003455:Cryptococcus neoformans / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D004271:DNA, Fungal / Q000037:antagonists & inhibitors* / Q000378:metabolism; D008826:Microbial Sensitivity Tests; D059807:S Phase Cell Cycle Checkpoints / Q000187:drug effects*; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D014249:Trichophyton / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism
chemical_list: D000935:Antifungal Agents; D023181:Antimicrobial Cationic Peptides; D004271:DNA, Fungal
keywords: Antifungal; Antimicrobial peptide; Candida albican; Cell cycle; DNA binding