APPARENT CO-OPERATIVE EFFECT OF ACETYL-COA ON SHEEP KIDNEY PYRUVATE CARBOXYLASE
APPARENT CO-OPERATIVE EFFECT OF ACETYL-COA ON SHEEP KIDNEY PYRUVATE CARBOXYLASE
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DOI：
10.1016/0006-291x(66)90186-0
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发表时间：
1966-01-01
影响因子：
3.1
通讯作者：
LING, AM
中科院分区：
文献类型：
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作者：
BARRITT, GJ;KEECH, DB;LING, AM
丙酮酸羧化酶（丙酮酸：CD 2连接酶（ADP），EC 6.4。1.1.）已从四种不同来源分离，a.禽肝线粒体（Utter和Keech，1963），绵羊肾皮质线粒体（Ling和Keech，1966），面包酵母（Ruiz-Amil et.例如，1965）和香茅假单胞菌（Seubert和Remberger，1961）。肝脏和肾脏酶都表现出对乙酰辅酶A的绝对需求，据报道，乙酰辅酶A表现出经典的米氏动力学（Keech和Utter，1963）。酵母酶在不存在乙酰基ZoA的情况下是有活性的，但是CoA或其乙酰基衍生物能够诱导酶活性的两倍刺激（Ruiz-Amil &. &., 1965年）。动力学数据表明，乙酰辅酶A发挥变构效应或诱导酶的构象变化。在乙酰辅酶A存在下，碳酸氢盐的表观米氏常数的变化（库珀和本尼迪克特，1966）被归因于蛋白质三级结构的变化。已证明细菌酶不需要乙酰辅酶A。
The enzyme pyruvate carboxylase(pyruvate: CD2 ligase(ADP), EC 6.4. 1.1.) has been isolated from four different sources, a, avian liver mitochondria (Utter and Keech, 1963), sheep kidney cortical mitochondria(Ling and Keech, 1966), bakers’ yeast (Ruiz-Amil et. al., 1965) and Pseudomonas citronellolis (Seubert and Remberger, 1961). The liver and kidney enzymes both exhibit an absolute requirement for acetylCoA which has been reported to exhibit classical Michaelis-Menten kinetics(Keech and Utter, 1963). The yeast enzyme is active in the absence of acetylZoA but either CoA or its acetyl derivative are capable of inducing a two-fold stimulation of enzymic activity(Ruiz-Amil &. &., 1965). It has been suggested from kinetic data that acetyl-CoA exerts either an allosteric effect or induces a conformational change in the enzyme. A change in the apparent Michaelis constant for bicarbonate in the presence of acetylCoA(Cooper and Benedict, 1966) has been attributed to a’change in the tertiary structure of the protein. No acetyl-CoA requirement has been demonstrated for the bacterial enzyme.