Symmetry Distortion in the Human Hemoglobin Tetramer Induced by Asymmetric Ligation
Symmetry Distortion in the Human Hemoglobin Tetramer Induced by Asymmetric Ligation
复制标题
不对称连接引起的人血红蛋白四聚体的对称性畸变
DOI：
10.1016/j.febslet.2011.11.027
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发表时间：
2012
期刊：
影响因子：
3.5
通讯作者：
Naoya Shibayama.
中科院分区：
文献类型：
--
作者：
小井川浩之;鎌形清人;新井宗仁;飯島一生;芳坂貴弘;高橋聡;金丸周司,伊藤悠太,有坂文雄;新井宗仁;Naoya Shibayama.
为了研究人四聚体（αβ）2血红蛋白与前两种配体结合后的构象变化，我们用CO结合的Fe（II）-Ni（II）杂化物和无β-β交联的Fe（II）-Ni（II）杂化物测定了4种四聚体血红蛋白的4，4 ′-二硫代二吡啶与β 93 Cys巯基之间的反应动力学。数据显示，所有配位中间体都具有高的巯基反应性，其大于或等于完全配位终态的反应性，尤其是当含有配位α亚基时。结果还表明，两种不对称（α1β1和α1β2）连接的物种显示出相似的高速率巯基反应性和两相动力学，表明一种新的构象，但不对称连接仅引起轻微的功能畸变。
To investigate the conformational changes in human tetrameric (αβ)2hemoglobin upon binding of the first two ligands, we have measured the kinetics of reactions between 4,4′-dithiodipyridine and β93Cys sulfhydryl groups of four diliganded hemoglobins by using CO-bound Fe(II)–Ni(II) hybrids with and without β-β cross-linking. The data show that all the diliganded intermediates have high sulfhydryl reactivities, which are greater than or equal to that for the fully-liganded end state, especially when containing liganded α subunit(s). The results also reveal that both the asymmetrically (α1β1 and α1β2) diliganded species show similar high rates of sulfhydryl reactivity and biphasic kinetics, suggesting a new conformation but only slight functional distortion caused by asymmetric ligation.