Szabo A, Karplus M
Biochemistry. 1975 Mar 11;14(5):931-40. doi: 10.1021/bi00676a009.
An allosteric model proposed previously for structure-function relations in hemoglobin is applied to the analysis of low- and high-spin valency hybrids. By assuming that the low-spin oxidized chains have the tertiary structure of oxygenated chains while the high-spin oxidized chains have a tertiary structure intermediate between that of deoxygenated and oxygenated chains, the model parameters associated with the different valency hybrids can be obtained, and their equilibrium properties can be estimated. The hybrid results are used also to provide an interpretation of methemoglobin and its ligand replacement reactions and of the oxidation-reduction equilibrium of normal hemoglobin. For the various systems studied it is found that the effects of pH and 2,3-diphosphoglycerate are in agreement with the model.
先前提出的用于分析血红蛋白结构-功能关系的变构模型，被应用于低自旋和高自旋价态杂合体的分析。通过假设低自旋氧化链具有氧合链的三级结构，而高自旋氧化链具有介于脱氧链和氧合链之间的三级结构，可以获得与不同价态杂合体相关的模型参数，并估计它们的平衡性质。杂合体的结果还用于解释高铁血红蛋白及其配体置换反应，以及正常血红蛋白的氧化还原平衡。对于所研究的各种系统，发现pH值和2,3-二磷酸甘油酸的影响与该模型一致。
