[Study of the iron-sulfur center N-2 from NADH-dehydrogenase in different metabolic states of the mitochondria from liver and heart].
The structural--equilibrium and nonequilibrium forms of the center N-2 from NADH-dehydrogenase differ in their parametres of the spin-lattice relaxation. The curves of the temperature dependence of the ESR signal intensity become the effective method of the study of the iron-sulphur proteins. The structural nonequilibrium form of the center N-2 was observed in the "4th" metabolic (by Chance) state, but equilibrium form of the center N-2 prevailed in the "3d" state or in the uncoupled state.