Stereospecific oxidation of secondary alcohols by human alcohol dehydrogenases.

摘要: The human liver alpha alcohol dehydrogenase exhibits a different substrate specificity and stereospecificity for secondary alcohols than the beta 1 1, gamma or horse dehydrogenases. All of enzymes efficiently oxidize primary alcohols, but oxidizes far more dehydrogenase. Specifically, four- five-carbon with efficiencies 0.06-2.2 times that homologs these up to 3 orders magnitude greater those three other isoenzymes. Whereas isoenzymes show distinct preference toward (S)-(+)-3-methyl-2-butanol, isoenzyme prefers (R)-(-)-3-methyl-2-butanol. Computer-simulated graphics demonstrate subunit accommodates (S)-(+)-3-methyl-2-butanol within active site much better opposite stereoisomer, primarily due steric hindrance caused by Phe-93. Human may accommodate (R)-(-)-3-methyl-2-butanol because close contacts between latter Thr-48. These observations suggest substitutions at positions 93 48 in determine their alcohols.