Isolation and characterisation of bacterial strains containing enantioselective DMSO reductase activity: application to the kinetic resolution of racemic sulfoxides.
The kinetic resolution of racemic sulfoxides by dimethyl sulfoxide (DMSO) reductases was investigated with a range of microorganisms. Three bacterial isolates (provisionally identified as Citrobacter braakii, Klebsiella sp. and Serratia sp.) expressing DMSO reductase activity were isolated from environmental samples by anaerobic enrichment with DMSO as terminal electron acceptor. The organisms reduced a diverse range of racemic sulfoxides to yield either residual enantiomer depending upon the strain used. C. braakii DMSO-11 exhibited wide substrate specificity that included dialkyl, diaryl and alkylaryl sulfoxides, and was unique in its ability to reduce the thiosulfinate 1,4-dihydrobenzo-2, 3-dithian-2-oxide. DMSO reductase was purified from the periplasmic fraction of C. braakii DMSO-11 and was used to demonstrate unequivocally that the DMSO reductase was responsible for enantiospecific reductive resolution of racemic sulfoxides.
Department of Biological Sciences, The University of Warwick, Coventry, CV4 7AL, UK. hluckarift@gulf.net
Heather R
HR
Luckarift
Howard
H
Dalton
Narain D
ND
Sharma
Derek R
DR
Boyd
Robert A
RA
Holt
D002954:Citrobacter / Q000145:classification / Q000201:enzymology* / Q000302:isolation & purification / Q000378:metabolism; D004783:Environmental Microbiology; D007506:Iron-Sulfur Proteins / Q000302:isolation & purification* / Q000378:metabolism*; D007709:Klebsiella / Q000145:classification / Q000201:enzymology* / Q000302:isolation & purification / Q000378:metabolism; D008970:Molecular Weight; D010088:Oxidoreductases / Q000302:isolation & purification* / Q000378:metabolism*; D021122:Protein Subunits; D012705:Serratia / Q000145:classification / Q000201:enzymology* / Q000302:isolation & purification / Q000378:metabolism; D013237:Stereoisomerism; D013379:Substrate Specificity; D013454:Sulfoxides / Q000737:chemistry / Q000378:metabolism*
D007506:Iron-Sulfur Proteins; D021122:Protein Subunits; D013454:Sulfoxides; D010088:Oxidoreductases; C045664:dimethyl sulfoxide reductase