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Differential susceptibility of human alcohol dehy drogenase isoenzymes to anions
Author(s) -
Bühler R.,
Von Wartburg J.-P.
Publication year - 1984
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(84)80610-9
Subject(s) - chemistry , alcohol , isozyme , differential (mechanical device) , biochemistry , enzyme , physics , thermodynamics
Human liver alcohol dehydrogenase (ADH) isoenzymes β 1 β 1 , γ 1 γ 1 from Caucasian individuals with ‘typical’ ADH and β 2 β 2 ‐Bern from Caucasian individuals with ‘atypical’ phenotype differed in their susceptibility to anions. At pH 7.0 β 1 β 1 and γ 1 γ 1 were more active in Tris‐HCl buffer than in sodium phosphate buffer but less active in Hepes‐NaOH and Mops‐NaOH. β 2 β 2 ‐Bern showed the same activity in all these buffers. At pH 7.0 and at low concentrations (50–100 mM) chloride activated the ethanol oxidation by β 1 β 1 and γ 1 γ 1 , whereas sulfate showed no effect. At anion concentrations above 100 mM all isoenzymes were inhibited. At pH 10.5 β 1 β 1 and γ 1 γ 1 were not activated. Measuring the acetaldehyde reduction, no comparable activation by chloride was observed; all three isoenzymes were inhibited, at significantly lower anion concentrations. These anion effects can be correlated with the different primary structures of the isoenzymes around the active site and the coenzyme binding site.