Site-directed mutagenesis of the hinge region of nisinZ and properties of nisinZ mutants

• Published in: Applied microbiology and biotechnology Vol. 64; no. 6; pp. 806 - 815
• Main Authors: Yuan, J, Zhang, Z.Z, Chen, X.Z, Yang, W, Huan, L.D
• Format: Journal Article
• Language: English
• Published: Berlin Springer 01.06.2004; Springer Nature B.V
• Subjects: Amino Acid Sequence; Amino acids; Anti-Bacterial Agents - chemistry; Anti-Bacterial Agents - pharmacology; Antimicrobial agents; antimicrobial properties; Bacteria; Biological and medical sciences; Biotechnology; Circular Dichroism; Drug Stability; food preservatives; functional properties; Fundamental and applied biological sciences. Psychology; High temperature; Microbial Sensitivity Tests; Microbiology; Micrococcus - drug effects; Micrococcus flavus; Molecular Sequence Data; Mutagenesis; Mutagenesis, Site-Directed; Mutants; nisin; Nisin - analogs & derivatives; Nisin - chemistry; Nisin - genetics; Nisin - pharmacology; nisZ gene; physicochemical properties; Proteins; Pseudomonas; Pseudomonas - drug effects; Salmonella; Shigella; Shigella - drug effects; site-directed mutagenesis; Solubility; Streptococcus - drug effects; Streptococcus thermophilus; structural genes; Structure-Activity Relationship; Nisin; Mutation; Bacteriocin; Site directed mutagenesis
• ISSN: 0175-7598; 1432-0614
• DOI: 10.1007/s00253-004-1599-1

To study the role of the hinge region in nisin and to obtain mutants that exhibit altered or new biological activities and functional properties, we changed certain amino acids in the hinge region by performing site-directed mutagenesis with the nisinZ structural gene (nisZ). The results showed that the nisinZ mutants had decreased antimicrobial activities against Micrococcus flavus NCIB8166 and Streptococcus thermophilus. Interestingly, compared with wild nisinZ, mutant N20K nisinZ and M21K nisinZ displayed antimicrobial activity against gram-negative Shigella, Pseudomonas and Salmonella; and they had a higher solubility than wild-type nisinZ. At pH 8, the solubilities of N20K nisinZ and M21K nisinZ were, respectively, three-fold higher and five-fold higher than that of nisinZ. Mutant N20Q nisinZ and M21G nisinZ were considerably more stable than nisinZ at higher temperatures and neutral or alkaline pH. These mutants provided information that the central hinge region in nisinZ plays an important role in providing the conformational flexibility required for the antimicrobial activity on the membrane. Our finding documented that it may well be worth considering the construction of the new nisin mutants with changed inhibitory activity against a wide range of gram-negative bacteria and the improvement of functional properties by site-directed mutagenesis.