Coletta M, Ascenzi P, Castagnola M, Giardina B
Department of Molecular Cellular and Animal Biology, University of Camerino Via Filippo Camerini 2, Italy.
J Mol Biol. 1995 Jun 16;249(4):800-3. doi: 10.1006/jmbi.1995.0338.
The effect of pH and/or organic phosphate on the kinetics of O2 dissociation from oxygenated human hemoglobin and on the spectroscopic features shown by the ferrous nitrosylated derivative of human hemoglobin has been investigated. The results indicate the occurrence of conformational change(s) taking place in liganded ferrous hemoglobin, bringing about a faster kinetic ligand dissociation process, accompanied by the appearance of peculiar spectroscopic features of the ferrous nitrosylated hemoglobin. Altogether these functional and spectroscopic observations indicate the existence of a nesting of tertiary and/or quaternary conformations in the liganded forms of human hemoglobin which may account for the action of heterotropic effectors, such as protons and organic phosphates.
研究了pH值和/或有机磷酸盐对氧合人血红蛋白中氧气解离动力学以及人血红蛋白亚硝基化亚铁衍生物所显示的光谱特征的影响。结果表明，在配位亚铁血红蛋白中发生了构象变化，导致动力学配体解离过程加快，同时出现了亚硝基化亚铁血红蛋白特有的光谱特征。这些功能和光谱观察结果共同表明，人血红蛋白的配位形式中存在三级和/或四级构象的嵌套，这可能解释了质子和有机磷酸盐等异源效应剂的作用。
