Aldolase

Abstract

Abstract Two commercial kits for the measurement of serum aldolase activity by a spectrophotometric (UV) method were evaluated. Neither was satisfactory in their present forms, since aldolase activity was not rate-limiting in one, and side reactions utilizing NADH occurred in the other. A study was made of the optimum concentrations of substrate, NADH, buffer, and coupled enzymes (triosephosphate isomerase and α-glycerophosphate dehydrogenase) in the procedure utilized by one kit, and a method based upon these findings is proposed. The key feature of the proposed method is an increase in the amount of the auxiliary enzymes, GDH/TIM, so that aldolase becomes the rate-limiting enzyme. The proposed method also differs from the kit procedure in the concentrations of substrate and NADH, in the choice of buffer, volume of reaction mixture, and in the order of adding solutions to the reaction mixture.