[Free radical reactions and energy transformation in microsome membranes. Arrhenius equation for the monooxygenase reaction].
The mechanism of coupling of the oxidation and activation of membrane enzymes was considered. It is obvious that microsomal monooxygenase uses the energy of NADPH oxidation for the activation of the terminal agent--cytochrome P-450. However, till now the mechanism of the transformation of this energy has not been discussed. It is supposed that the coupling process includes transformation of oxidation energy to kinetic energy, the energy of lipid pulsations. The mechanism proposed by us and the mechanism of energy transformation according to Mitchell are two independent mechanisms, both being of fundamental importance for biochemistry and biophysics of membranes. One approach uses the dielectric properties of membrane, and the other is based on the ability of hydrocarbon chains of phospholipids for rotamerization. A new empirical Arrhenius equation for membrane processes is offered. It accounts for the ability of membrane to reserve the energy in kinetic form (internal temperature). In conditions when membrane proteins cease to be acceptors of energy, the transfer of energy, i.e., transformation of the energy of NADPH oxidation into heat or light, occurs.
Biological Department Lomonosov Moscow State University, Vorob'evy Gory, Moscow, 119899 Russia.
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Dmitriev
D004734:Energy Metabolism; D005609:Free Radicals / Q000378:metabolism; D007425:Intracellular Membranes / Q000201:enzymology / Q000378:metabolism*; D007501:Iron / Q000378:metabolism; D007700:Kinetics; D008051:Lipid Bilayers / Q000378:metabolism; D008563:Membrane Lipids / Q000378:metabolism*; D008861:Microsomes / Q000201:enzymology / Q000378:metabolism*; D010084:Oxidation-Reduction; D013816:Thermodynamics; D014810:Vitamin E / Q000378:metabolism
D005609:Free Radicals; D008051:Lipid Bilayers; D008563:Membrane Lipids; D014810:Vitamin E; D007501:Iron