title: Synthesis and secretory expression of hybrid antimicrobial peptide CecA-mag and its mutants in Pichia pastoris.
abstract: The hybrid peptide CA(1-7)-M(2-12) gene was designed according to the N-terminal 1-7 amino acid sequence of the antimicrobial peptide cecropin A (CA) and the N-terminal 2-12 amino acid sequence of maganin (M) and synthesized using Pichia pastoris preferred codons. The gene was cloned into pPICZαA and transformed into the P. pastoris recipient bacterium SMD1168, regulated by the alcohol oxidase (AOX). Expression of the cecA-mag hybrid antimicrobial peptide (MW, 1.9 kDa) revealed broad-spectrum antibiotic activity and to the ability to inhibit growth of most G(-) and G(+) bacteria. Three mutants of cecA-mag were designed and synthesized by recombination polymerase chain reaction site-directed mutagenesis to investigate the relationship between the structure and function of this antimicrobial peptide. The inhibition titers of these mutants against Staphylococcus aureus were evaluated using the agar diffusion method. Under the conditions of the same concentration and volume, the bacteriostatic diameters of three cecA-mag mutants were 1.2, 1.2 and 1.5 times, respectively, compared with the diameters of wild-type cecA-mag.
authors.affiliation: School of Clinical Laboratory of Medicine of Ningxia Medical University, Yinchuan, Ningxia 750004, China.
authors.forename: Xiuqing
authors.initials: X
authors.lastname: Wang
authors.forename: Mingxing
authors.initials: M
authors.lastname: Zhu
authors.forename: Aijun
authors.initials: A
authors.lastname: Zhang
authors.forename: Fengqin
authors.initials: F
authors.lastname: Yang
authors.forename: Puyan
authors.initials: P
authors.lastname: Chen
mesh_terms: D000595:Amino Acid Sequence; D000890:Anti-Infective Agents / Q000378:metabolism / Q000494:pharmacology; D023181:Antimicrobial Cationic Peptides / Q000096:biosynthesis* / Q000138:chemical synthesis / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D001483:Base Sequence; D004591:Electrophoresis, Polyacrylamide Gel; D054806:Magainins / Q000096:biosynthesis* / Q000235:genetics / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D009154:Mutation; D010843:Pichia; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis* / Q000378:metabolism / Q000494:pharmacology
chemical_list: D000890:Anti-Infective Agents; D023181:Antimicrobial Cationic Peptides; D054806:Magainins; D011993:Recombinant Fusion Proteins; C031161:cecropin A