Non-stereoselective decomposition of (±)-S-alk(en)yl-l-cysteine sulfoxides to antibacterial thiosulfinates catalyzed by C115H mutant methionine γ-lyase from Citrobacter freundii.

S-Alk(en)yl-l-cysteine sulfoxides, initially found in plants of the genus Allium, are converted to antimicrobial thiosulfinates by pyridoxal 5'-phosphate(PLP)-dependent alliinase (EC 4.4.1.

Engineered Citrobacter freundii methionine γ-lyase effectively produces antimicrobial thiosulfinates.

Antimicrobial activity of thiosulfinates in situ produced by mixtures of Citrobacter freundii methionine γ-lyase (MGL) with new substrates, l-methionine and S-(alkyl/allyl)-l-cysteine sulfoxides has been recently demonstrated (Anufrieva et al., 2015). This opens a way to the rational design of a new biotechnologically relevant antimicrobial drug producer.