title: Thermodynamics of antimicrobial peptide JCpep8 binding to living Staphylococcus aureus as a pseudo-stationary phase in capillary electrochromatography and consequences for antimicrobial activity.
abstract: To understand the details of the permeation pathways of antimicrobial peptide JCpep8, the antimicrobial processes were investigated step by step in this paper. First, the characterization of the initial binding process was explored by introducing the living Staphylococcus aureus cells (LSACs) into electrophoretic buffer used as pseudo-stationary phase in capillary electrochromatography (CEC), and the thermodynamic parameters were determined. The binding constants at 298, 303, and 309 K were 7.40 × 10¹¹, 1.43 × 10¹², and 2.6 × 10¹² M⁻¹, respectively, which indicated the evident interaction between JCpep8 and LSACs. This binding process was spontaneous. Both the electrostatic force and hydrophobic effect play major roles in this binding process. Second, antibacterial activity kinetics and outer membrane and inner membrane disruption assays were investigated. Data indicated that JCpep8 killed microbes principally by breaking their cell wall and membrane, followed by cell lysis. The results were confirmed by Fourier transform infrared (FTIR) spectroscopy and transmission electron microscopy (TEM). In summary, JCpep8 kills microbes mainly by wall-/membrane-targeting pore-forming mechanisms.
authors.affiliation: State Key Laboratory of Food Science and Technology and School of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, People's Republic of China.
authors.forename: Jianhui
authors.initials: J
authors.lastname: Xiao
authors.forename: Hui
authors.initials: H
authors.lastname: Zhang
authors.forename: Shaodong
authors.initials: S
authors.lastname: Ding
mesh_terms: D000890:Anti-Infective Agents / Q000378:metabolism* / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides / Q000378:metabolism* / Q000494:pharmacology*; D053801:Capillary Electrochromatography; D002462:Cell Membrane / Q000187:drug effects / Q000648:ultrastructure; D002473:Cell Wall / Q000187:drug effects / Q000648:ultrastructure; D009842:Oligopeptides / Q000378:metabolism* / Q000494:pharmacology*; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000378:metabolism* / Q000648:ultrastructure; D013816:Thermodynamics
chemical_list: D000890:Anti-Infective Agents; D023181:Antimicrobial Cationic Peptides; D009842:Oligopeptides; C574986:cysteinyl-alanyl-isoleucyl-leucyl-threonyl-histidyl-lysyl-arginine