一磷酸腺苷对骨骼肌果糖1,6 - 二磷酸酶的抑制作用。

The inhibition of skeletal-muscle fructose 1,6-diphosphatase by adenosine monophosphate.

Opie L H, Newsholme E A

Biochem J. 1967 Aug;104(2):353-60. doi: 10.1042/bj1040353.

Abstract

The present study extends the finding of Krebs & Woodford (1965) that muscle fructose diphosphatase is more sensitive to AMP inhibition than liver fructose diphosphatase. 2. Hen breast fructose diphosphatase has a K(i) for AMP of 0.1mum; the plot of percentage inhibition is non-sigmoid and the reciprocal plot of activity against AMP concentration is sometimes linear. 3. Percentage inhibition plots for other muscle fructose diphosphatases are sigmoid curves which exhibit different threshold responses to the AMP concentration. 4. The intracellular content of AMP in all muscles tested exceeds the inhibition concentration range of AMP. 5. The sensitivity of muscle fructose diphosphatase to AMP inhibition is decreased by the presence of Mg(2+) or Mn(2+) ions; in the presence of Mn(2+) the inhibition curve for hen breast fructose diphosphatase becomes sigmoid. 6. From the formation constants for the Mg(2+) and Mn(2+) chelates, the effect of these ions in chelation of AMP can be calculated. Although chelation of AMP can explain the Mg(2+) effect, it cannot explain the marked relief of AMP inhibition by Mn(2+). 7. It is suggested that Mn(2+) has a specific effect on this enzyme which reduces the sensitivity to AMP inhibition.

摘要

本研究扩展了克雷布斯和伍德福德（1965年）的发现，即肌肉中的果糖二磷酸酶比肝脏中的果糖二磷酸酶对AMP抑制更敏感。2. 母鸡胸肌果糖二磷酸酶对AMP的抑制常数（K(i)）为0.1微摩尔；抑制百分比曲线不是S形的，活性对AMP浓度的倒数曲线有时是线性的。3. 其他肌肉果糖二磷酸酶的抑制百分比曲线是S形曲线，对AMP浓度表现出不同的阈值反应。4. 所有测试肌肉中的细胞内AMP含量超过了AMP的抑制浓度范围。5. Mg(2+)或Mn(2+)离子的存在会降低肌肉果糖二磷酸酶对AMP抑制的敏感性；在Mn(2+)存在下，母鸡胸肌果糖二磷酸酶的抑制曲线变为S形。6. 根据Mg(2+)和Mn(2+)螯合物的形成常数，可以计算出这些离子对AMP螯合的影响。虽然AMP的螯合可以解释Mg(2+)的作用，但它不能解释Mn(2+)对AMP抑制的显著缓解作用。7. 有人提出，Mn(2+)对这种酶有特定作用，可降低对AMP抑制的敏感性。