Dependence of the substrate specificity and kinetic mechanism of horse-liver alcohol dehydrogenase on the size of the C-3 pyridinium substituent. 3-Benzoylpyridine-adenine dinucleotide.
The kinetic mechanism and the substrate specificity of liver alcohol dehydrogenase are changed when 3-benzoylpyridine-adenine dinucleotide is used as coenzyme. Only primary alcohols are substrates of the enzyme and with ethanol the mechanism becomes rapid-equilibrium random bi-bi. According to model building experiments on a graphic display, the benzoyl group partially enters the substrate binding site, whereas the essential interactions between coenzyme and enzyme are preserved. This restraint on the substrate binding site provides a molecular explanation for the observed dependence between coenzyme and substrate chemical structures.
D000426:Alcohol Dehydrogenase / Q000032:analysis*; D000818:Animals; D001665:Binding Sites; D003067:Coenzymes / Q000494:pharmacology*; D006736:Horses; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D008954:Models, Biological; D009243:NAD / Q000031:analogs & derivatives* / Q000494:pharmacology; D013379:Substrate Specificity
D003067:Coenzymes; D009243:NAD; C050094:3-benzoylpyridine-adenine dinucleotide; D000426:Alcohol Dehydrogenase