Conditions leading to precipitation of ribulose bisphosphate carboxylase-oxygenase differ from those leading to enzyme activation

The relation between conditions leading to precipitation and/or activation of Ru-P2 carboxylase have been explored in order to test the hypothesis that conformational changes leading to precipitation might be identical to those which are presumed to lead to enzyme activation. From the results of kinetic and solubility studies, we conclude that this hypothesis is not valid, since changes in solubility of Ru-P2 carboxylase occur ten times as fast as changes in enzyme kinetics.