Madb. Navaratna et al., Two-component anti-Staphylococcus aureus lantibiotic activity produced by Staphylococcus aureus C55, APPL ENVIR, 64(12), 1998, pp. 4803-4808
Staphylococcus aureus C55 was Shown to produce bacteriocin activity compris
ing three distinct peptide components, termed staphylococcins C55 alpha, C5
5 beta, and C55 gamma. The three peptides were purified to homogeneity by a
simple four-step purification procedure that consisted of ammonium sulfate
precipitation followed by XAD-2 and reversed-phase (C-8 and C-18) chromato
graphy. The yield following C-8 chromatography was about 86%, with a more-t
han-300-fold increase in specific activity. When combined in approximately
equimolar amounts, staphylococcins C55 alpha and C55 beta acted synergistic
ally to kill S. aureus or Micrococcus luteus but not S. epidermidis strains
. The N-terminal amino acid sequences of all three peptides were obtained a
nd staphylococcins C55 alpha and C55 beta were shown to be lanthionine-cont
aining (lantibiotic) molecules with molecular weights of 3,339 and 2,993, r
espectively. The C55 gamma peptide did not appear to be a lantibiotic, nor
did it augment the inhibitory activities of staphylococcin C55 alpha and/or
C55 beta. Plasmids of 2.5 and 32.0 kb are present in strain C55, and follo
wing growth of this strain at elevated temperature (42 degrees C), a large
proportion of the progeny failed to produce strong bacteriocin activity and
also lost the 32.0-kb plasmid. Protoplast transformation of these bacteria
with purified 32-kb plasmid DNA regenerates the ability to produce the str
ong bacteriocin activity.