A method and a preparation for the determination of the enzymic activity of co-comp-nadh, redox enzyme

摘要

1,136,733. Determination of carbonyl compound-NADH 2 redox enzyme. CHUGAI SEIYAKU K.K. 4 May, 1966 [11 May, 1965 (2)], No. 19726/66. Heading B1X. The activity of a carbonyl compound -NADH 2 redox enzyme is determined by coupling together a malic dehydrogenase reaction and a carbonyl compound-NADH 2 redox reaction and measuring the amount of oxalacetic acid formed. The mechanism is:- The oxalacetic acid may be measured using a diazonium salt, for example 4-amino-2, 5-diethoxybenzanilide diazonium chloride. 6-benzamide-4-methoxy-m-toluidine diazonium chloride, tetrazotised o-di-anisidine, optionally with an inorganic metal sa or by decomposing the oxalacetic acid with a mixture of aniline and citric acid and either measuring the carbon dioxide evolved or reacting the pyruvic acid formed with 2,4-dinitrophenylhydrazine. A typical composition for adding to the test solution comprises a carbonyl compound, NADH 2 , malic acid, malic dehydrogenase, a colour developer agent responsive to oxalacetic acid and a buffer composition to maintain the pH between 7 and 9. Malic acid (or its salt), NADH 2 and the carbonyl compound may be used in molar ratio 300-500: 0.5-2: 30-60. Examples refer to determination of lactic dehydrogenase, α-hydroxybutyric dehydrogenase. Also mentioned are alcohol dehydrogenase, triose phosphate dehydrogenase, glutamic dehydrogenase.