title: In vitro and in vivo characterization of a new recombinant antimicrobial peptide, MP1102, against methicillin-resistant Staphylococcus aureus.
abstract: Currently, more antimicrobial drug candidates are urgently needed to combat the rise in drug-resistance among pathogenic microbes. A new antimicrobial peptide, MP1102, a variant of NZ2114, was designed, evaluated, and overexpressed in Pichia pastoris. The total secreted protein in cultures reached 695 mg/l, and the concentration of the recombinant MP1102 (rMP1102) was 292 mg/l. rMP1102 was purified from the fermentation supernatant by one-step cation exchange chromatography to obtain a yield of 197.1 mg/l with 96.4 % purity. rMP1102 exhibited potent activity against Gram-positive bacteria, and its minimum inhibitory concentrations (MICs) for four Staphyloccocus aureus (S. aureus) strains ranged from 0.028 to 0.11 μM, and it had stronger activity (MIC = 0.04 to 0.23 μM) to 20 clinical isolates of MRSA (cMRSA) than rNZ2114 (MIC = 0.11 to 0.90 μM). rMP1102 was shown to kill over 99.9 % of tested S. aureus cells within 6 h when treated at one, two, and four times its MIC and over 90 % of S. aureus cells within 12 h at concentrations of 5, 10, and 20 mg/kg in a mouse thigh infection model. The higher sensitivity of MRSA to MP1102 than to its parental peptide, NZ2114, indicated by this initial pharmacodynamic analysis suggests a possible difference in the killing mechanism of these two molecules. rMP1102 caused less than 0.05 % hemolytic activity at 128 μg/ml and exhibited good thermostability from 20 to 80 °C, with its highest activity being observed at pH 8.0. These results suggest that this yeast expression system is feasible for large-scale production, and rMP1102 exerted stronger activity against S. aureus than NZ2114 via a different mechanism and exhibited potential as a new antimicrobial agent for S. aureus, especially MRSA infections.
authors.affiliation: Key Laboratory of Feed Biotechnology, Ministry of Agriculture, 100081, Beijing, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhang
authors.forename: Da
authors.initials: D
authors.lastname: Teng
authors.forename: Xiumin
authors.initials: X
authors.lastname: Wang
authors.forename: Ruoyu
authors.initials: R
authors.lastname: Mao
authors.forename: Xintao
authors.initials: X
authors.lastname: Cao
authors.forename: Xiaoyuan
authors.initials: X
authors.lastname: Hu
authors.forename: Lifen
authors.initials: L
authors.lastname: Zong
authors.forename: Jianhua
authors.initials: J
authors.lastname: Wang
mesh_terms: D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000235:genetics / Q000302:isolation & purification / Q000494:pharmacology*; D002852:Chromatography, Ion Exchange; D004195:Disease Models, Animal; D015870:Gene Expression; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects* / Q000502:physiology; D051379:Mice; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability / Q000187:drug effects; D010843:Pichia / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000494:pharmacology; D013203:Staphylococcal Infections / Q000382:microbiology*
chemical_list: D023181:Antimicrobial Cationic Peptides; D011994:Recombinant Proteins