Biopolymers and cell. 1991. Volume 7. № 5. 42 - 51

MOSTOVNIKOV V. A., MOSTOVNIKOVA G. R., PLAVSKH V. Yu., TRET'YAKOV S. A.

The Effect of Molecular Air Oxygen on the Enzymatic Activity of NADH-Dependent Dehydrogenases

Summary

    A new effect, the dependence of the rate of the enzymatic biochemical reaction of py-ruvate transformation to lactate catalyzed by lactatedehydrogenase (LDH) in the pre¬sence of reduced nicotinamidadeninedinucleotide (NADH) on the concentration of air oxygen (62) dissolved in the reaction medium, are reported. It is shoun that this ef¬fect is due to the dinucleotide with molecules O2 complex formation. It is found that the molecular oxygen removal from the coenzyme solution lead to the NADH spatial structure change. Changes, induced by molecular oxygen, are reversible. The dependence of the rate enzymatic biochemical reaction on concentration of dissolved oxygen has not been observed in the case of lactate-pyruvate transformation reaction catalysed by LDH in the presence of nicotinamidadeninedinucleotide (NAD+). There have not been observed the NAD+ with 0? molecules complexes formation.