Anion Binding to Liver Alcohol Dehydrogenase

Residual activity in carboxymethylated liver alcohol dehydrogenase.

The physiological role of liver alcohol dehydrogenase.

1. Yeast alcohol dehydrogenase was used to determine ethanol in the portal and hepatic veins and in the contents of the alimentary canal of rats given a diet free from ethanol. Measurable amounts of a substance behaving like ethanol were found. Its rate of interaction with yeast alcohol dehydrogenase and its volatility indicate that the substance measured was in fact ethanol. 2. The mean alcoho...

Kinetic studies of liver alcohol dehydrogenase.

1. NADH2 prepared by enzymic reduction of pure NAD by the method of Rafter & Colowick (1957), and isolated as the sodium salt, gives higher maxrimum rates of reduction of acetaldehyde with liver alcohol dehydrogenase at pH 6 than a number of commercial preparations of high purity. Maximum values of 2-4 for the extinction ratio E260/E340 and 2% for the proportion of inactive material absorbing a...

Coenzyme Interaction with Horse Liver Alcohol Dehydrogenase EVIDENCE FOR ALLOSTERIC COENZYME BINDING SITES FROM THERMODYNAMIC

The techniques of fluorescence enhancement, fluorescence quenching, fluorescence polarization, and equilibrium dialysis are utilized to study the binding properties of coenzyme to horse liver alcohol dehydrogenase. Polarization of fluorescence and equilibrium dialysis show that NADH binds to alcohol dehydrogenase with a stoichiometry of 6 mol per mol of enzyme, in contrast to the value of 2 det...

pH-dependent Conformational States of Horse Liver Alcohol Dehydrogenase*

The quenching of liver alcohol dehydrogenase protein fluorescence at alkaline pH indicates two conformational states of the enzyme with a pK,, of 9.8 -t0.2, shifted to 10.6 f 0.2 in I&O. NAD’ and 2-p-toluidinonaphthalene-6-sulfonate, a fluorescent probe competitive with coenzyme, bind to the acid conformation of the enzyme. The pK,, of the proteinfluorescence quenching curve is shifted toward 7...