Compensational dependence of activation parameters of membrane enzymes

The activation parameters of reactions catalyzed by various membrane enzymes have been analyzed. In all cases there was compensational dependence between the enthalpy and the entropy of the reactions catalyzed. The differences found between lipid-activated, lipid-nonactivated, and water-soluble enzymes are discussed. A method of calculating the volume changes involved in reaction activation is proposed. It is concluded that to maintain catalysis, enzymes activated by lipids and incorporated into a liquid-crystal lipid bilayer require the least reconstruction in a protein-solvent system.