title: Luminescence studies on the conformational behavior of horse-liver alcohol dehydrogenase.
abstract: The luminescence quenching and conformational behaviour of alcohol dehydrogenase from horse liver upon substrate binding has been studied. It was shown that the binding of NADH and NAD+ to the enzyme resulted in the quenching of Trp-314 luminescence, whereas the luminescence of Trp-15 was not quenched. In this case nonradiating energy transfer from Trp-314 to NADH was observed. An essential energy transfer from Trp-15 to NADH and between the two Trp-314 residues of both subunits of the enzyme was not revealed. The quenching of the enzyme luminescence upon NAD+ binding was caused mainly, by NAD+ reduction to NADH. It was assumed that the release of the proton upon NAD+ binding occurred due to the reduction. Binding of ethanol, ADP or adenosine did not result in essential conformational changes of the enzyme.
mesh_terms: D000241:Adenosine / Q000378:metabolism; D000244:Adenosine Diphosphate / Q000378:metabolism; D000426:Alcohol Dehydrogenase; D000429:Alcohol Oxidoreductases; D000818:Animals; D004735:Energy Transfer; D000431:Ethanol / Q000378:metabolism; D006736:Horses; D008099:Liver / Q000201:enzymology*; D008163:Luminescent Measurements; D008433:Mathematics; D009243:NAD / Q000378:metabolism; D011487:Protein Conformation; D014364:Tryptophan
chemical_list: D009243:NAD; D000431:Ethanol; D000244:Adenosine Diphosphate; D014364:Tryptophan; D000429:Alcohol Oxidoreductases; D000426:Alcohol Dehydrogenase; D000241:Adenosine