[Influence of several metabolites on A4 and B4-isoenzymes of loach lactate dehydrogenase activity depending on the direction of the isoenzyme-catalyzed reaction].
Various concentration of fructose-1.6-diphosphate, malate, oxaloacetate, creatine phosphate, ATP, ADP and AMP were studied for their effect on the activity of A4-and B4-isoenzymes of lactate dehydrogenase (LDH, EC 1, 1. 1. 27) produced from skeletal muscles and unfertilized egg cells of Misgurnus fossilis in the reactions of lactate oxidation and pyruvate reduction. It was found that oxaloacetate, creatine phosphate, ADP and AMP decreased the activity of A- and B-type isoenzymes to a different extent. The value of the inhibitory action depended not only on the concentration of the substances and subunit composition of the isoenzymes but also depended on the direction of the reaction they catalyse. Malate and fructose-1.6-diphosphate did not inhibit the activity of A4 isoenzyme in the lactate oxidation and malate and ATP did not influence the activity of the former and of B4-isoenzymes in this reaction. At the same time malate, fructose-1.6-diphosphate and ATP decreased the activity of the investigated isoenzymes in the pyruvate reduction reactions.
D000227:Adenine Nucleotides / Q000494:pharmacology; D000818:Animals; D005260:Female; D005399:Fishes; D005635:Fructosediphosphates / Q000494:pharmacology; D007527:Isoenzymes; D007700:Kinetics; D007770:L-Lactate Dehydrogenase / Q000378:metabolism*; D008293:Malates / Q000494:pharmacology; D009132:Muscles / Q000201:enzymology*; D009865:Oocytes / Q000201:enzymology*; D010071:Oxaloacetates / Q000494:pharmacology; D010710:Phosphates / Q000494:pharmacology; D010725:Phosphocreatine / Q000494:pharmacology
D000227:Adenine Nucleotides; D005635:Fructosediphosphates; D007527:Isoenzymes; D008293:Malates; D010071:Oxaloacetates; D010710:Phosphates; D010725:Phosphocreatine; C030298:malic acid; D007770:L-Lactate Dehydrogenase; C029063:fructose-1,6-diphosphate
Vliianie nekotorykh metabolitov na aktivnost' A4- i B4-izofermentov laktatdegidrogenazy v'iuna v zavisimosti ot napravleniia kataliziruemoĭ imi reaktsii.