title: Design and pharmacodynamics of recombinant NZ2114 histidine mutants with improved activity against methicillin-resistant Staphylococcus aureus.
abstract: NZ2114 is a promising candidate for therapeutic application owing to its potent activity to Staphylococcus aureus. Our objective was to identify NZ2114 derivatives with improved activity through substitution of His16 and His18 with residues Arginine and Lysine. Eight mutants were designed and expressed in Pichia pastoris X-33 via pPICZαA. Five of them exhibited strong antimicrobial activity against S. aureus at low minimal inhibitory concentrations (MICs) of 0.057-0.454 μM. Among them, H1, H2, and H3 showed ideal pharmacodynamic effects on methicillin-resistant S. aureus ATCC43300.  The total protein level of H1, H2, and H3 reached 1.70, 1.77 and 1.54 g/l at 120 h of induction in the 5-l fermenter, respectively. They killed over 99.9% of pathogens within 1.5 h at 2× and 4× MIC. The post antibiotic effect of H1, H2 and H3 to S. aureus ATCC43300 was 2.94, 1.75 and 1.55 h at 2× MIC, which was similar with their original peptide NZ2114 (1.43 h) and vancomycin (1.72 h). The fractional inhibitory concentration index (FICI) indicated indifferent effects between H1, H2, H3 and vancomycin, ampicillin, rifampicin. Additionally, they had low hemolysis and high stability in different environments (temperature, pH, proteases, and saline ions). All results indicate that H1, H2, and H3 can be produced in large-scale and have potential as therapeutic drugs against MRSA.
authors.affiliation: Institute of Animal Nutrition, Northeast Agricultural University, Harbin, 150030, China.|Key Laboratory of Feed Biotechnology, Ministry of Agriculture, Beijing, 100081, China.|Gene Engineering Laboratory, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
authors.forename: Huixian
authors.initials: H
authors.lastname: Chen
authors.affiliation: Key Laboratory of Feed Biotechnology, Ministry of Agriculture, Beijing, 100081, China. rain_mry@126.com.|Gene Engineering Laboratory, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, China. rain_mry@126.com.
authors.forename: Ruoyu
authors.initials: R
authors.lastname: Mao
authors.affiliation: Key Laboratory of Feed Biotechnology, Ministry of Agriculture, Beijing, 100081, China.|Gene Engineering Laboratory, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
authors.forename: Da
authors.initials: D
authors.lastname: Teng
authors.affiliation: Key Laboratory of Feed Biotechnology, Ministry of Agriculture, Beijing, 100081, China.|Gene Engineering Laboratory, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
authors.forename: Xiumin
authors.initials: X
authors.lastname: Wang
authors.affiliation: Key Laboratory of Feed Biotechnology, Ministry of Agriculture, Beijing, 100081, China.|Gene Engineering Laboratory, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
authors.forename: Ya
authors.initials: Y
authors.lastname: Hao
authors.affiliation: Institute of Animal Nutrition, Northeast Agricultural University, Harbin, 150030, China. fengxingjun2008@163.com.
authors.forename: Xingjun
authors.initials: X
authors.lastname: Feng
authors.affiliation: Key Laboratory of Feed Biotechnology, Ministry of Agriculture, Beijing, 100081, China. wangjianhua@caas.cn.|Gene Engineering Laboratory, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, China. wangjianhua@caas.cn.
authors.forename: Jianhua
authors.identifier: http://orcid.org/0000-0002-4048-6055
authors.initials: J
authors.lastname: Wang
keywords: Antimicrobial peptide; NZ2114; Pharmacodynamics; Staphylococcus aureus