STANDARD FREE-ENERGY CHANGE FOR THE HYDROLYSIS OF THE ALPHA,BETA-PHOSPHOANHYDRIDE BRIDGE IN ATP
STANDARD FREE-ENERGY CHANGE FOR THE HYDROLYSIS OF THE ALPHA,BETA-PHOSPHOANHYDRIDE BRIDGE IN ATP
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DOI：
10.1021/bi00036a001
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发表时间：
1995-09-12
期刊：
影响因子：
2.9
通讯作者：
ARABSHAHI, A
中科院分区：
文献类型：
--
作者：
FREY, PA;ARABSHAHI, A
1993; Lehninger等人，1992;加勒特& Grisham，1994; Voet & Voet，1990;马修斯&货车Holde，1990）。此外，许多教科书还列出了PP水解的标准自由能AG '=-7.9 ~8.0 kcal mol-1。然而，焦磷酸盐水解的真实值明显不那么负（Flodgaard & Fleron，1974）。因此，ATP水解为AMP和PP的标准自由能变化必须大于8 kcal mol-1，本文对此作了解释。通过查阅文献，我们发现ATP水解为AMP和PP…的标准自由能变化比常规值负得多，比ATP水解为ADP和P…的标准自由能变化负得多。这一事实在代谢和酶如氨酰-tRNA合成酶、NAD+焦磷酸化酶、核苷酸糖焦磷酸化酶、PRPP合成酶、DNA连接酶和RNA连接酶以及DNA和f的作用机制中具有重要意义。
1993; Lehninger et al., 1992; Garrett & Grisham, 1994; Voet & Voet, 1990; Matthews & Van Holde, 1990). Moreover, many textbooks also list the standard free energy for the hydrolysis of PP¡ as AG'=—7.9 to 8.0 kcal mol-1. However, thetrue value for pyrophosphate hydrolysis is significantly less negative (Flodgaard & Fleron, 1974). Therefore, the standard free energy change for the hydrolysis of ATP to AMP and PP¡ must be more negative than 8 kcal mol-1, as is explained in this paper. Upon consulting the literature, we have found that the standard free energy change for the hydrolysis of ATP to AMP and PP¡ is much more negative than the conventional value and much more negative than that for the hydrolysis of ATP to ADP and P¡. This fact has significant implications in metabolism and for the mechanisms of action of enzymes such as aminoacyl-tRNA synthetases, NAD+ pyrophosphorylase, nucleotide sugar pyrophosphorylases, PRPP synthetase, DNA ligases, and RNA ligases, as well as DNA and f Supported by Grant No. GM30840 from the National Institute of General Medical Sciences.