[A flavin-containing monooxygenase from  Schizosaccharomyces pombe : characterization and application in the synthesis of  S -methyl-L-cysteine sulfoxide].
 S -methyl-L-cysteine sulfoxide (SMCO) is a non-protein sulfur-containing amino acid with a variety of functions. There are few reports on the enzymes catalyzing the biosynthesis of SMCO from  S -methyl-L-cysteine (SMC). In this study, the flavin-containing monooxygenase gene derived from  Schizosaccharomyces pombe  ( spfmo ) was heterologously expressed in  Escherichia coli  BL21(DE3) and the enzymatic properties of the expressed protein were analyzed. The optimum catalytic conditions of the recombinant SpFMO were 30 ℃ and pH 8.0, under which the enzyme activity reached 72.77 U/g. An appropriate amount of Mg 2+  improved the enzyme activity. The enzyme kinetic analysis showed that the  K  m  and  k  cat / K  m  of SpFMO on the substrate SMC were 23.89 μmol/L and 61.71 L/(min·mmol), respectively. Under the optimal reaction conditions, the yield of SMCO synthesized from SMC catalyzed by SpFMO was 12.31% within 9 h. This study provides reference for the enzymatic synthesis of SMCO.
Lian M, Song Z, Gao W, Zhu G, Dong M, Li Y, Liu Y, Wang F, Lu F