The effect of 2H2O on the quaternary structure of the fatty acid synthetase multienzyme complex

The effect of 2H2O on the cold-induced dissociation and cold-induced inactivation of fatty acid synthetase from lactating mammary gland has been studied. The rate constants for these reactions were almost identical and were lowered in media containing 2H2O. The results have been interpreted to indicate that inactivation of the enzyme in the cold is a direct result of dissociation into subunits and that maintenance of the native structure of the enzyme is limited by the strength of hydrophobic bonds.