Snechkute M A, Glemzha A A
Biokhimiia. 1976 Mar;41(3):491-5.
Investigation of the effect of different buffer systems on the rate of alpha-ketoglutarate decarboxylase reaction have shown that the pH optimum is 6.8 in tris-maleic, tris-H3PO4 and KH2PO4-KOH buffers, and it is 7.5 in imidazole buffer. The highest reaction rate was observed when using phosphate containing buffers. The increase of phosphate concentration increased considerably the rate of alpha-ketoglutarate decarboxylase reaction. Mg2+ and Ca2+ were shown to affect slightly the reaction rate. Co2+ and Ag+ slightly inactivated the enzyme. Cu2+ turned to be a very efficient inhibitor of alpha-ketoglutarate decarboxylase reaction. Apparent Mikhaelis constants are determined to be 1.6-10(-3) M for alpha-ketoglutaric acid and 1.7-10(-2)M for 2,6-dichlorphenolindophenol.
对不同缓冲系统对α-酮戊二酸脱羧酶反应速率影响的研究表明，在三羟甲基氨基甲烷-马来酸、三羟甲基氨基甲烷-H₃PO₄和KH₂PO₄-KOH缓冲液中，最适pH值为6.8，而在咪唑缓冲液中为7.5。使用含磷酸盐缓冲液时观察到最高反应速率。磷酸盐浓度的增加显著提高了α-酮戊二酸脱羧酶反应的速率。Mg²⁺和Ca²⁺对反应速率有轻微影响。Co²⁺和Ag⁺使酶略有失活。Cu²⁺被证明是α-酮戊二酸脱羧酶反应的一种非常有效的抑制剂。α-酮戊二酸的表观米氏常数测定为1.6×10⁻³M，2,6-二氯酚靛酚的表观米氏常数为1.7×10⁻²M。
