Thissen J, Desai S, McCartney P, Komuniecki R
Mol Biochem Parasitol. 1986 Nov;21(2):129-38. doi: 10.1016/0166-6851(86)90016-2.
An improved purification scheme for the isolation of the Ascaris suum pyruvate dehydrogenase complex directly from body wall muscle has been developed which yields a fully activated pyruvate dehydrogenase complex with substantial PDHa kinase activity. The apparent Km for coenzyme A (CoA) is much lower than previously reported and can only be accurately measured in the presence of a CoA-regenerating system. The alpha-pyruvate dehydrogenase subunit of the ascarid complex is unique and its migration on sodium dodecylsulfate polyacrylamide gels is altered after phosphorylation. PDHa kinase activity is inhibited by ADP, thiamine pyrophosphate, and physiological levels of pyruvate and propionate. In contrast, PDHa kinase activity is stimulated by elevated NADH/NAD+ and acetyl CoA/CoA ratios, although it appears that the NADH/NAD+ ratios required for half-maximal stimulation are more than an order of magnitude greater than those reported for mammalian pyruvate dehydrogenase complexes.
已开发出一种改进的纯化方案，可直接从体壁肌肉中分离猪蛔虫丙酮酸脱氢酶复合物，该方案可产生具有大量丙酮酸脱氢酶激酶活性的完全活化的丙酮酸脱氢酶复合物。辅酶A（CoA）的表观Km远低于先前报道的值，并且只能在CoA再生系统存在的情况下准确测量。蛔虫复合物的α-丙酮酸脱氢酶亚基是独特的，其在十二烷基硫酸钠聚丙烯酰胺凝胶上的迁移在磷酸化后会发生改变。丙酮酸脱氢酶激酶活性受到ADP、硫胺素焦磷酸以及生理水平的丙酮酸和丙酸盐的抑制。相反，丙酮酸脱氢酶激酶活性受到升高的NADH/NAD +和乙酰辅酶A/辅酶A比率的刺激，尽管似乎半最大刺激所需的NADH/NAD +比率比哺乳动物丙酮酸脱氢酶复合物报道的比率大一个数量级以上。
