Absence of cooperative energy at the heme in liganded hemoglobins.
Absence of cooperative energy at the heme in liganded hemoglobins.
复制标题
配体血红蛋白中血红素缺乏协同能量。
DOI：
10.1021/bi00308a003
复制
发表时间：
1984
期刊：
影响因子：
2.9
通讯作者：
Noble,RW
中科院分区：
文献类型：
--
作者：
Rousseau,DL;Tan,SL;Ondrias,MR;Ogawa,S;Noble,RW
DL Rousseau,* S. L. Tan,* M. R. Ondrias, 8 S. Ogawa, and R. W. Noble abstract: Using resonance Raman and infrared absorption spectroscopies, we show that there are no energetically sig-nificant structural changes at the heme upon the quaternary structure transition in six-coordinatehemoglobins. These observations are at variance with the presently accepted mechanism for cooperativity, which postulates severe strain in the T quaternary structure of liganded hemoglobin. By consideration of the present results, and studies on deoxyhemoglobins and photodissociated hemoglobins, a view of the distribution of thefree energy of cooperativity emerges. InDespite many years of study, the molecular basis for co-operativity in hemoglobin is not understood (Rousseau & Ondrias, 1983). This results in part from the difficulty of studying allof the many possible interactions that could contribute to cooperativity. As a starting point, the quaternary structure dependent interactions at the binding site, ie, the heme-protein-ligand interactions, must be elucidated. Only then can the amount of cooperative energy localized at the heme be evaluated and routes of information transfer within the tetramer be revealed. In order to study protein-heme interactions it is helpful to consider independently three sep-
