Open AccessStereospecificity of the Dihydroorotate‐Dehydrogenase Reaction
Author(s) -
Blattmann Paul,
Rétey János
Publication year - 1972
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1972.tb02079.x
Subject(s) - dihydroorotate dehydrogenase , stereospecificity , chemistry , methylene , flavin group , sodium ethoxide , hydrogen atom , stereochemistry , catalysis , medicinal chemistry , substrate (aquarium) , hydrogen , photochemistry , enzyme , organic chemistry , pyrimidine , ethanol , group (periodic table) , biology , ecology
1 Dihydroorotate dehydrogenase from Zymobacterium oroticum is shown to catalyse the anti ‐elimination of hydrogen from the substrate. 2 In the presence of a catalytic amount of NAD + the enzyme catalyses the exchange between the abstractable hydrogen atoms of dihydroorotate and solvent protons, the exchange of (5 S )‐H atom being twice as fast as that of the 4‐H atom. 3 Sodium‐ethoxide‐catalysed exchange affects both diastereotopic protons in the methylene group of dihydroorotate, the (5 S )‐H atom being exchanged somewhat faster than the (5 R )‐H atom. 4 These findings are discussed in terms of stereospecificity and mechanism of flavin dependent dehydrogenase reactions.