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.
Uvarov VYu
Institute of Biological and Medical Chemistry, Academy of Medical Sciences of the USSR, Moscow.
Archakov
A I
AI
D000818:Animals; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D004337:Drug Carriers; D004789:Enzyme Activation / Q000502:physiology*; D004851:Epoxide Hydrolases / Q000378:metabolism; D005954:Glucosephosphate Dehydrogenase / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008081:Liposomes; D008565:Membrane Proteins / Q000378:metabolism*; D009251:NADPH-Ferrihemoprotein Reductase / Q000378:metabolism; D013696:Temperature
D004337:Drug Carriers; D008081:Liposomes; D008565:Membrane Proteins; D003577:Cytochrome P-450 Enzyme System; D007770:L-Lactate Dehydrogenase; D005954:Glucosephosphate Dehydrogenase; D009251:NADPH-Ferrihemoprotein Reductase; D004851:Epoxide Hydrolases