Sulfoxidation mechanism of vanadium bromoperoxidase from Ascophyllum nodosum. Evidence for direct oxygen transfer catalysis.

Content Provider	Semantic Scholar
Author	Brink, H. B. Ten Schoemaker, Hans Egbert Wever, Ron
Copyright Year	2001
Abstract	We have previously shown that vanadium bromoperoxidase from Ascophyllum nodosum mediates production of the (R)-enantiomer of methyl phenyl sulfoxide with 91% enantiomeric excess. Investigation of the intrinsic selectivity of vanadium bromoperoxidase reveals that the enzyme catalyzes the sulfoxidation of methyl phenyl sulfide in a purely enantioselective manner. The K(m) of the enzyme for methyl phenyl sulfide was determined to be approximately 3.5 mM in the presence of 25% methanol or tert-butanol. The selectivity of the sulfoxidation of methyl phenyl sulfide is optimal in the temperature range 25-30 degrees C and can be further optimized by increasing the enzyme concentration, yielding selectivities with up to 96% enantiomeric excess. Furthermore, we established for the first time that vanadium bromoperoxidase is functional at temperatures up to 70 degrees C. A detailed investigation of the sulfoxidation activity of this enzyme using (18)O-labeled hydrogen peroxide shows that vanadium bromoperoxidase mediates the direct transfer of the peroxide oxygen to the sulfide. A schematic model of the vanadium haloperoxidase sulfoxidation mechanism is presented.
File Format	PDF HTM / HTML
DOI	10.1046/j.1432-1327.2001.01856.x
PubMed reference number	11121113
Journal	Medline
Volume Number	268
Issue Number	1
Alternate Webpage(s)	http://www1.udel.edu/chem/polenova/VHPO/V_bromoper_Wever_2001.pdf
Alternate Webpage(s)	https://doi.org/10.1046/j.1432-1327.2001.01856.x
Journal	European journal of biochemistry
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article