Abaturov L V, Molchanova T P, Nosova N G, Shliapnikov S V, Faĭzulin D A
Mol Biol (Mosk). 2006 May-Jun;40(3):468-81.
The rate of the H-D exchange of the peptide NH atoms of the isolated alpha and beta subunits of human Hb were studied at the pH range 5.5-9.0 and 20 degrees C by the IR spectroscopy. The factor retardation of the exchange rate of subunits -P in the range -10(2)-10(7). In comparison with tetramer Hb the probability of local fluctuations (1/P) is increased to a slightly greater extent for the monomeric alpha subunits then for the tetramer beta subunits. Unlike Hb oxygenation of subunits does not influence on the probability of the local fluctuations and subunits have no the pH-dependent change of the value 1/P observable for the ligand Hb. The possible mechanisms of the overall intensification of the local fluctuations upon the splitting of the Hb tetrameric contacts between subunits are discussed with the inviting of the structural crystallographic data.
通过红外光谱研究了在5.5 - 9.0的pH范围和20℃下，人血红蛋白分离的α和β亚基的肽NH原子的H-D交换速率。亚基 -P的交换速率的阻滞因子在-10(2)-10(7)范围内。与四聚体血红蛋白相比，单体α亚基的局部波动概率(1/P)的增加幅度略大于四聚体β亚基。与血红蛋白不同，亚基的氧合不影响局部波动的概率，并且亚基没有配体血红蛋白可观察到的1/P值的pH依赖性变化。结合结构晶体学数据讨论了亚基间血红蛋白四聚体接触分裂后局部波动总体增强的可能机制。
