Burns D H, Aberhart D J
Worcester Foundation for Experimental Biology, Shrewsbury, Massachusetts 01545.
Anal Biochem. 1988 Jun;171(2):339-45. doi: 10.1016/0003-2697(88)90495-2.
A rapid, continuous spectrophotometric method has been developed for the assay of decarboxylases. The assay uses a coupled enzyme system in which liberated CO2 is reacted with phosphoenolpyruvate and phosphoenolpyruvate carboxylase to form oxaloacetate, which in turn is reduced by malate dehydrogenase to L-malate concomitantly with the oxidation of NADH to NAD. The resultant decrease in absorbance at 340 nm accurately reflects the activity of the decarboxylase. The method is capable of detecting the liberation of as little as 1 nmol of CO2/min and was tested in assays of lysine decarboxylase, orotidine-5'-phosphate decarboxylase, and 4'-phosphopantothenoyl-L-cysteine decarboxylase.
已开发出一种快速、连续的分光光度法用于脱羧酶的测定。该测定使用一种偶联酶系统，其中释放的二氧化碳与磷酸烯醇丙酮酸和磷酸烯醇丙酮酸羧化酶反应形成草酰乙酸，草酰乙酸进而被苹果酸脱氢酶还原为L-苹果酸，同时NADH氧化为NAD。在340nm处吸光度的下降准确反映了脱羧酶的活性。该方法能够检测低至1nmol二氧化碳/分钟的释放量，并已在赖氨酸脱羧酶、乳清酸核苷-5'-磷酸脱羧酶和4'-磷酸泛酰-L-半胱氨酸脱羧酶的测定中进行了测试。
