Dissociation and rate constants of some human liver alcohol dehydrogenase isoenzymes.
ADH from human liver forms binary complexes with NADH, associated with a blue shift of the peak of the fluorescence emission of NADH. The wavelength shift is the same for all isoenzymes but the accompanying intensification of the fluorescence is different. The fluorescence is further increased by the formation of the very tight ternary enzyme-NADH-isobutyramide complexes. These properties are similar to those for the horse liver ADH, as well as the molecular weight of E=40 000 per active site of the dimer molecule (EE). "Stopped-flow" determined velocity constants (ER in equilibrium E+R) were found to be in good agreement with ethanol activity constants previously determined by activity measurement, confirming the validity of the ordered ternary complex mechanism also for the human ADH. No single isoenzyme activity as high as that reported by Mourad and Woronick or Drum has been found.
D000429:Alcohol Oxidoreductases / Q000032:analysis / Q000378:metabolism*; D006801:Humans; D007527:Isoenzymes / Q000032:analysis / Q000378:metabolism*; D008099:Liver / Q000032:analysis / Q000201:enzymology*; D008970:Molecular Weight; D009243:NAD; D013050:Spectrometry, Fluorescence
D007527:Isoenzymes; D009243:NAD; D000429:Alcohol Oxidoreductases