Potential Role of Non-Specific Snail Muscle Adenylate Deaminase in Operating of NADH-Dependent Dehydrogenases
The discovery of an unspecific adenylate deaminase in snail foot muscle, an enzyme deaminating ADP, ATP and NADH in addition to AMP, endowed with a very high affinity towards substrates and present in a huge amount in snail muscle, gave a task for investi-gation on the metabolic role of de amino-NADH, which can be easily produced in this tissue. Several years ago Buniatian described direct deamination of NADH and NAD by “crude mitochondrial fractions” of rat brain and liver. He proposed the cyclic deamination of NAD and its reamination by forming NAD-succinate complex (with asparate) as a way for free ammonia liberation from amino acids,2 analogically to Lowenstein’s well-known purine nucleotide cycle.3 It was also described that reduced nicotinamide hypoxanthine dinucleotide (deaminoNADH) can be oxidized 20–40 times faster than NADH by intact rat liver mitochondria, while both reduced coenzymes were oxidized to the same extent by sonicated mitochondria.4 There were also suggestions concerning the effect of deamino NADH on the rate of the reaction catalyzed by NADH-dependent dehydrogenases.
KeywordsLactate Dehydrogenase Malate Dehydrogenase Helix Pomatia Metabolic Role Muscle Extract
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- 1.A. Stankiewicz, Proc. IV Int. Symp. Human Purine Pyrimidine Metab. Maastricht (1982).Google Scholar
- 2.H.C. Buniatian, in “Handbook of Neurochemistry,” A. Lajtha, ed., Plenum Press, New York, 3: 399–413 (1972).Google Scholar
- 5.M.E. Pullmann, S.P. Colowick, and N.O. Kaplan, J. Biol. Chem. 194: 593–602 (1952).Google Scholar