松鼠鱼血红蛋白的动力学与平衡。一种因大亚基异质性而复杂化的根效应血红蛋白。

The kinetics and equilibria of squirrel-fish hemoglobin. A Root effect hemoglobin complicated by large subunit heterogeneity.

作者信息

Pennelly R R, Riggs A, Noble R W

出版信息

Biochim Biophys Acta. 1978 Mar 28;533(1):120-9. doi: 10.1016/0005-2795(78)90555-x.

Abstract

The functional properties of squirrel-fish hemoglobin have been measured by studying ligand binding equilibria and kinetics. The results show that squirrel-fish hemoglobin has a Root effect with a corresponding stabilization of the low affinity state. The properties of this state are pH dependent even in the absence of cooperativity. The effect of ATP shifts the overall ligant affinity towards the low affinity state and is characteristic of the allosteric effect caused by organic phosphates. Under pH and ATP conditions favoring the low affinity conformational state, a 10-fold difference in the binding kinetics of carbon monoxide to the alpha and beta subunits is observed.

摘要

通过研究配体结合平衡和动力学，测定了松鼠鱼血红蛋白的功能特性。结果表明，松鼠鱼血红蛋白具有鲁特效应，同时低亲和力状态相应稳定。即使在没有协同性的情况下，该状态的特性也依赖于pH值。ATP的作用使整体配体亲和力向低亲和力状态转变，这是有机磷酸盐引起的变构效应的特征。在有利于低亲和力构象状态的pH值和ATP条件下，观察到一氧化碳与α和β亚基结合动力学存在10倍的差异。