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.