Saturation mutagenesis of lysine 12 leads to the identification of derivatives of nisin A with enhanced antimicrobial activity

Molloy, Evelyn M.; Field, Des; O'Connor, Paula M.; Cotter, Paul D.; Hill, Colin; Ross, R. Paul

Saturation mutagenesis of lysine 12 leads to the identification of derivatives of nisin A with enhanced antimicrobial activity

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Files

EMM_SaturationPV2013.pdf(326.55 KB)

Date

2013

Authors

Molloy, Evelyn M.

Field, Des

O'Connor, Paula M.

Cotter, Paul D.

Hill, Colin

Ross, R. Paul

Publisher

Public Library of Science

Published Version

10.1371/journal.pone.0058530

Abstract

It is becoming increasingly apparent that innovations from the "golden age'' of antibiotics are becoming ineffective, resulting in a pressing need for novel therapeutics. The bacteriocin family of antimicrobial peptides has attracted much attention in recent years as a source of potential alternatives. The most intensively studied bacteriocin is nisin, a broad spectrum lantibiotic that inhibits Gram-positive bacteria including important food pathogens and clinically relevant antibiotic resistant bacteria. Nisin is gene-encoded and, as such, is amenable to peptide bioengineering, facilitating the generation of novel derivatives that can be screened for desirable properties. It was to this end that we used a site-saturation mutagenesis approach to create a bank of producers of nisin A derivatives that differ with respect to the identity of residue 12 (normally lysine; K12). A number of these producers exhibited enhanced bioactivity and the nisin A K12A producer was deemed of greatest interest. Subsequent investigations with the purified antimicrobial highlighted the enhanced specific activity of this modified nisin against representative target strains from the genera Streptococcus, Bacillus, Lactococcus, Enterococcus and Staphylococcus.

Keywords

Gram positive pathogens , Precursor lipid Ii , Lantibiotic nisin , Listeria monocytogenes , Lactococcus lactis , Innate resistance , Peptide pisin , In vitro , Gene , Antibiotics

Citation

Molloy EM, Field D, Connor PMO, Cotter PD, Hill C, Ross RP (2013) Saturation Mutagenesis of Lysine 12 Leads to the Identification of Derivatives of Nisin A with Enhanced Antimicrobial Activity. PLoS ONE 8(3): e58530. doi:10.1371/journal.pone.0058530