Citrulline synthesis: regulation by alterations in the total mitochondrial adenine nucleotide content.
Citrulline synthesis: regulation by alterations in the total mitochondrial adenine nucleotide content.
复制标题
瓜氨酸合成：通过改变线粒体腺嘌呤核苷酸总量进行调节。
DOI：
10.1016/0003-9861(82)90433-7
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发表时间：
1982
影响因子：
3.9
通讯作者：
Aprille,JR
中科院分区：
文献类型：
--
作者：
Goldstein,FG;Aprille,JR
在体外大范围内改变大鼠肝线粒体的总腺嘌呤核苷酸含量，以研究总基质ATP+ ADP+ AMP含量的净变化与瓜氨酸合成总速率之间的可能关系。分离的线粒体通过与无机焦磷酸盐一起孵育而特异性地耗尽基质腺嘌呤核苷酸（GK Asimakis和JR Aprille，1980，Arch. Biochem. Biophys. 203，307-316）;或者，通过在30° C下用1 m m ATP孵育线粒体来增加基质腺嘌呤核苷酸。在随后用于测定瓜氨酸合成的孵育中不包括外源性ATP或ADP。速率在0.1 - 1.6 μmol瓜氨酸/mg蛋白/h之间变化，是腺嘌呤核苷酸总含量的线性函数，范围为2-15 nmol（ATP+ ADP+ AMP）/mg蛋白。基质ATP+ ADP+ AMP含量的进一步增加不会导致瓜氨酸合成速率的进一步增加。总腺嘌呤核苷酸含量的变化反映在基质中ATP和ADP含量的成比例变化中。ATP/ADP比值无明显变化。因此，瓜氨酸合成的变化最简单地解释为不同浓度的ATP对氨甲酰磷酸合成酶活性的影响。得出的结论是，总腺嘌呤核苷酸含量的净变化有助于瓜氨酸合成的控制。这些发现是显着的背景下，最近的证据表明，基质腺嘌呤核苷酸池的大小是激素的控制。
The total adenine nucleotide content of rat liver mitochondria was varied in vitro over a wide range in order to investigate a possible relationship between net changes in the total matrix ATP+ ADP+ AMP content and the overall rate of citrulline synthesis. Isolated mitochondria were specifically depleted of matrix adenine nucleotides by incubating with inorganic pyrophosphate (GK Asimakis and JR Aprille, 1980, Arch. Biochem. Biophys. 203, 307–316); alternatively, matrix adenine nucleotides were increased by incubating mitochondria with 1 m m ATP at 30° C. No exogenous ATP or ADP was included in the subsequent incubations for the determination of citrulline synthesis. Rates varied from 0.1 to 1.6 μmol citrulline/mg protein/h as a linear function of total adenine nucleotide content in the range 2–15 nmol (ATP+ ADP+ AMP)/mg protein. Further increases in the matrix ATP+ ADP+ AMP content caused no further increase in citrulline synthesis rates. Changes in the total adenine nucleotide content were reflected in proportional changes in both the ATP and ADP content of the matrix. The ATP ADP ratio did not change significantly. Therefore, the variations in citrulline synthesis were most simply explained as the effect of different concentrations of ATP on the activity of carbamoyl-phosphate synthetase. It was concluded that net changes in the total adenine nucleotide content can contribute to the control of citrulline synthesis. These findings are significant in the context of recent evidence which shows that the matrix adenine nucleotide pool size is under hormonal control.