Determination Methods Of Adenosine Deaminase (ADA) Activity And Its Application

ADA which has important relationships with the immune system of the body, is a kind of catabolic enzymes of nucleic acid. ADA can specifically catalyze adenosine to generate irreversible deamination. By analyzing the decreasing amount of the substrate or the increasing amount of the resultant in unit time, three determination methods of the ADA have been studied.With the combination of orthogonal designs and single factor design, optimal determination programs have been established. These methods have been applied to clinical assay with satisfactory results.Determination of ADA Activity in Body Fluids by Four Enzymic Coupling Method. While NH3 and Inosine are produced with adenosine as the substrate and adenosine deaminase as the reaction enzyme, three enzymic reactions are coupled: Inosine is converted to Xanthine with Nucleoside phosphorylase(PNP) as the reaction enzyme, and Xanthine is further converted to H₂O₂ with Xanthine Oxidase(XOD) as the reaction enzyme. With Trinder reaction, a red quinonoid compound is produced with peroxi-dase(POD) as the reaction enzyme. The third method employed in the determination of the ADA activity is by the determination of the increasing rate of absorbance at 500nm, or the increasing rate of red quinonoid compound. The optimal condition of enzymic reaction is explored by the combination of one factor design and orthogonal designs. As a result, a method of determination of ADA is developed which can be used for either manual manipulation or automatic biochemistry analysator. When pH7.40, the concentrations of adenosine and PNP in the substract solution, C₆H₅OH, POD and XOD in the color developing reagent are 6.00×10^-3mol/L,42U/L,1.50g/L, 5500U/L,20U/L respectively,...