Ligand binding properties of horse hemoglobins containing deutero- and mesoheme.
Ligand binding properties of horse hemoglobins containing deutero- and mesoheme.
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含有后血红素和中血红素的马血红蛋白的配体结合特性。
DOI：
10.1016/s0021-9258(17)33924-8
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发表时间：
1976
期刊：
影响因子：
--
通讯作者：
Q. Gibson
中科院分区：
文献类型：
--
作者：
D. Seybert;K. Moffat;Q. Gibson
马珠蛋白重组与原，氘，和mesoheme的反应已被检查的平衡和动力学方法。在几乎所有研究的反应中，中血红蛋白表现出更极端的功能行为，而次血红蛋白表现出与天然血红蛋白非常相似或介于两者之间的行为。我们的动力学和平衡结果表明，血红素修饰对血红蛋白的功能特性的主要影响是改变脱氧和配体构象的固有反应性。然而，血红素修饰不会导致两种状态之间的构象平衡发生实质性改变。简单的诱导电子效应的2-和4-取代基的血红素部分在氘和mesohemoglobin显然是不足以解释所观察到的平衡和动力学性质完全，这表明，这些取代基的空间效应也可能发挥作用，在确定血红蛋白分子的功能行为。
The reactions of horse globin reconstituted with proto-, deutero-, and mesoheme have been examined by equilibrium and kinetic methods. In virtually all reactions studied, mesohemoglobin displays the more extreme functional behavior, whereas deuterohemoglobin exhibits behavior which is either very similar to native hemoglobin or intermediate between the two. Our kinetic and equilibrium results indicate that the primary effect of heme modification on the functional properties of hemoglobin is to alter the intrinsic reactivities of the deoxy and liganded conformations. Heme modification does not, however, result in substantial alterations in the conformational equilibrium between the two states. Simple inductive electronic effects of the 2- and 4-substituents of the heme moiety in deutero- and mesohemoglobin are apparently not sufficient to explain the observed equilibrium and kinetic properties completely, which indicates that steric effects of these substituents may also play a role in determining the functional behavior of the hemoglobin molecule.