Open AccessPhosphate Binding to Liver Alcohol Dehydrogenase Studied by the Rate of Alkylation with Affinity Labels
Author(s) -
DAHL Knut H.,
MCKINLEYMCKEE John S.
Publication year - 1980
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1980.tb04287.x
Subject(s) - iodoacetic acid , chemistry , alcohol dehydrogenase , dissociation constant , phosphate , enzyme , dissociation (chemistry) , dehydrogenase , binding site , inorganic chemistry , medicinal chemistry , biochemistry , organic chemistry , receptor
In this work we report that phosphate anions interact with the anion binding site of alcohol dehydrogenase from horse liver. In protection experiments against the two affinity labels, iodoacetic acid and bromo‐imidazolylpropionic acid, the dissociation constant for the enzyme‐phosphate complex at pH 7.0 is, based on total phosphate, found to be 20 ± 5 mM. The 1,4‐piperazinediethanesulfonate anion has a lower affinity for the anion binding site, the dissociation constant at pH 7.0 being 130 ± 20 mM. The anion‐independent dissociation constants for the reversible enzyme‐affinity label complexes are at pH 7.0, 1.35 ± 0.2 mM for iodoacetic acid and 0.39 ± 0.05 mM for bromo‐imidazolylpropionic acid. These findings have important implications with respect to past and future work on this well known enzyme.