Concentration effects in assays of sheep liver mitochondrial aldehyde dehydrogenase and their interpretation in terms of enzyme dissociation
Dickinson, F.M.; Allanson, S.
Progress in Clinical and Biological Research 174: 71-81
1985
ISSN/ISBN: 0361-7742 PMID: 3983207 Document Number: 244586
Enzyme assays exhibit lag-phases during which the rate of acetaldehyde oxidation or p-nitrophenylacetate hydrolysis accelerates. A steady-state rate is achieved, but the time taken for this to occur increases as the enzyme concentration is decreased. With 0.009 microM enzyme this takes about 15 minutes. Analysis of experimental results suggests that the activation occurs because the tetrameric enzyme dissociates to a more active species. Gel filtration behaviour of the enzyme at different concentrations and stability tests with urea provide some general support for this hypothesis.