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

Non-stereoselective decomposition of (±)-S-alk(en)yl-L-cysteine sulfoxides to antibacterial thiosulfinates catalyzed by C115H mutant methionine γ-lyase from Citrobacter freundii. Biochimie. 2018 May 24;: Authors: Kulikova V, Morozova E, Rodionov A, Koval V, Anufrieva N, Revtovich S, Demidkina T Abstract 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 4.4.1.4). It was found that methionine γ-lyase (MGL, EC 4.4.1.11) catalyzes the β-elimination reaction of (±)-S-alk(en)yl-L-cysteine sulfoxides to yield thiosulfinates. The efficient catalyst for the production of thiosulfinates, C115H mutant MGL, developed in our previous work, cleaves S-alk(en)yl-L-cysteine sulfoxides more effectively than the wild type enzyme. Thiosulfinates generated by the C115H MGL/sulfoxide system have demonstrated growth inhibition of Gram-positive, Gram-negative bacteria and clinical isolates of pathogenic bacteria from mice. In search of a more effective system for production of antibacterial thiosulfinates we synthesized S-substituted analogues of L-cysteine sulfoxide with a longer side chains - (±)-S-propyl-L-cysteine sulfoxide ((±)-propiin) and (±)-S-n-butyl-L-cysteine sulfoxide ((±)-butiin) and determined catalytic parameters of the β-elimination reaction of two sulfoxides. It was found that C115H MGL cleaves (±)-...
Source: Biochimie - Category: Biochemistry Authors: Tags: Biochimie Source Type: research