Lanthionine Biosynthesis
Lantibiotics
are bacterial lanthionine-containing
antibiotic peptides of about 20 to 40 amino acids.
Lanthionines are special thioether
containing amino which are posttranslationally
introduced into peptides via dehydration of serines
and threonines and subsequent coupling of
these dehydrated residues to cysteine residues.
The thioether rings are
essential for lantibiotic
activity, furthermore they enhance the stability of the peptides by
protecting against proteolytic enzymes.
Lantibiotics are produced by- and mainly
active against Gram-positive bacteria. In view of the worldwide rise in
resistance to classical antibiotics, lantibiotics
might constitute a class of new antibiotics. The most well-known
lantibiotic is nisin,
which contains five (methyl)lanthionine
rings. It is applied as a food additive in more than fifty countries. The
(methyl)lanthionines
in nisin are synthesised
by a membrane associated enzyme cluster composed of a dehydrating enzyme,
a ring-forming enzyme, and a transporter. BiOMaDe researchers are focusing
on gaining full control of the enzyme complex in order to develop an
entirely biosynthetic means to introduce lanthionine
rings into peptides and proteins, thereby generating new peptide
antibiotics as well as to stabilizing therapeutic peptides and proteins
against proteolytic degradation.
