[Regulation of aldose reductase activity. The influence of effectors on reverse isomerization of the enzyme].

The effects of ligands of active and inhibitory centers of homogeneous aldose reductase from cattle eye lens on glucose reduction were studied. Using spectrophotometric titration and equilibrium gel filtration, the interaction of the enzyme active center with substrates was investigated. It was shown that the reaction kinetics obeys a mechanism with a quasi-equilibrium non-ordered attachment of substrates and isomerization of enzyme complexes with nicotinamide dinucleotide phosphates in the course of the catalytic act. It was found that the NADPH in equilibrium NADP equilibrium in the enzyme active center is shifted to the right; however, NADP dissociation may occur only as a result of the aldehyde reduction. The mechanisms of regulation of the enzyme activity by NADP, ADP and alpha-glycerol phosphate were proposed. It was shown that the binding of catalin and morine to the enzyme results in the inhibition of the enzymatic reaction and in the isomerization blocking. It was found that the inhibitory site of the isomeric form of aldose reductase displays a lower affinity for morine.