Deegan, LH,Suda, S,Lawton, EM,Draper, LA,Hugenholtz, F,Peschel, A,Hill, C,Cotter, PD,Ross, RP

2010

January

Microbial Biotechnology

Manipulation of charged residues within the two-peptide lantibiotic lacticin 3147

Validated

()

PRECURSOR LIPID-II CATIONIC ANTIMICROBIAL PEPTIDES SITE-DIRECTED MUTAGENESIS ALANYL-LIPOTEICHOIC ACID LACTOCOCCUS-LACTIS LISTERIA-MONOCYTOGENES ANTIBIOTIC-ACTIVITY CONFERS RESISTANCE STRUCTURAL GENE TEICHOIC-ACIDS

3

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Lantibiotics are antimicrobial peptides which contain a high percentage of post-translationally modified residues. While most attention has been paid to the role of these critical structural features, evidence continues to emerge that charged amino acids also play a key role in these peptides. Here 16 'charge' mutants of the two-peptide lantibiotic lacticin 3147 [composed of Ltn alpha (2+, 2-) and Ltn beta (2+)] were constructed which, when supplemented with previously generated peptides, results in a total bank of 23 derivatives altered in one or more charged residues. When examined individually, in combination with a wild-type partner or, in some instances, in combination with one another, these mutants reveal the importance of charge at specific locations within Ltn alpha and Ltn beta, confirm the critical role of the negatively charged glutamate residue in Ltn alpha and facilitate an investigation of the contribution of positively charged residues to the cationic Ltn beta. From these investigations it is also apparent that the relative importance of the overall charge of lacticin 3147 varies depending on the target bacteria and is most evident when strains with more negatively charged cell envelopes are targeted. These studies also result in, for the first time, the creation of a derivative of a lacticin 3147 peptide (Ltn beta R27A) which displays enhanced specific activity.

DOI 10.1111/j.1751-7915.2009.00145.x