α-酮酸脱氢酶复合体。XI. 肾、心和肝线粒体丙酮酸脱氢酶复合体调节特性的比较研究。
Alpha-keto acid dehydrogenase complexes. XI. Comparative studies of regulatory properties of the pyruvate dehydrogenase complexes from kidney, heart, and liver mitochondria.
作者信息
Linn T C, Pettit F H, Hucho F, Reed L J
出版信息
Proc Natl Acad Sci U S A. 1969 Sep;64(1):227-34. doi: 10.1073/pnas.64.1.227.
The activity of the multienzyme pyruvate dehydrogenase complexes, isolated from mitochondria of beef kidney, beef heart, and pork liver, is regulated by phosphorylation and dephosphorylation. Phosphorylation and concomitant inactivation of each of the three complexes are catalyzed by an ATP-specific kinase, and dephosphorylation and concomitant reactivation are catalyzed by a phosphatase. The phosphatase has been separated from the other component enzymes of each pyruvate dehydrogenase complex, and the three phosphatases are functionally interchangeable. The kinase has been isolated from the beef kidney complex, and it is functional with the beef heart and pork liver complexes. ADP is competitive with ATP, and the ADP effect is more pronounced with the kidney kinase than with the liver and heart kinases. Pyruvate protects strongly the heart and liver pruvate dehydrogenase complexes and, to a lesser extent, the kidney complex against inactivation by ATP. Pyruvate apparently exerts its effect on the pyruvate dehydrogenase component of the complex, rather than on the kinase.
从牛肾、牛心和猪肝线粒体中分离出的多酶丙酮酸脱氢酶复合体的活性受磷酸化和去磷酸化作用调控。三种复合体各自的磷酸化及伴随的失活由一种ATP特异性激酶催化，而去磷酸化及伴随的重新激活则由一种磷酸酶催化。磷酸酶已从每种丙酮酸脱氢酶复合体的其他组成酶中分离出来，且这三种磷酸酶在功能上可互换。激酶已从牛肾复合体中分离出来，它对牛心和猪肝复合体也有作用。ADP与ATP具有竞争性，且ADP对肾激酶的影响比对肝激酶和心激酶的影响更显著。丙酮酸能强烈保护心脏和肝脏的丙酮酸脱氢酶复合体，对肾脏复合体的保护作用稍弱，使其免受ATP导致的失活。丙酮酸显然是对复合体中的丙酮酸脱氢酶成分发挥作用，而非对激酶起作用。
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