[Temperature dependence of membrane-bound aldehyde dehydrogenase from Acinetobacter: effect of solubilization and chain length of the substrates].

The NADP+-dependent aldehyde dehydrogenase of intracytoplasmic membranes of Acinetobacter calcoaceticus shows a characteristic behaviour of its reaction velocities in dependence on temperature. The calculated "real" activation energies depend on the increasing chain-length of the homologous aldehydes and grow appropriate to the membrane-bound and to the micellar form of the enzyme with 6.2 and 7.3 kJ/mole CH2-group, respectively. The values of the activation energy of the membrane-bound enzyme are - for each aldehyde of the homologous series - 12 kJ/mole larger than those of the solubilized enzyme (present as mixed micelles of enzyme, cholate and bacterial phospholipids).