1.25 Å resolution crystal structures of human haemoglobin in the oxy, deoxy and carbonmonoxy forms
1.25 Å resolution crystal structures of human haemoglobin in the oxy, deoxy and carbonmonoxy forms
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DOI：
10.1016/j.jmb.2006.05.036
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发表时间：
2006-07-14
影响因子：
5.6
通讯作者：
Tame, Jeremy R. H.
中科院分区：
文献类型：
--
作者：
Park, Sam-Yong;Yokoyama, Takeshi;Tame, Jeremy R. H.
氧合血红蛋白（oxyHb）的晶体结构的最新改进是在1983年完成的，这个实空间改进模型和后来的R状态模型之间的差异已被解释为结晶伪像或许多子状态的证据。我们已经改进了脱氧，氧和碳一氧血红蛋白的模型，以1.25埃的分辨率，并与其他血红蛋白结构进行比较。结果表明，旧的结构反映了在细化中使用的软件，与新的结构的许多差异是不太可能的生理相关。我们的模型的准确性的提高澄清了NMR和X-射线研究oxyHb之间的分歧，NMR实验表明之间存在的氢键的α和β-亚基的远端组氨酸和氧配体。高分辨率晶体结构还揭示了两种亚基类型中的氢键，但具有微妙的不同几何形状，这可以解释当该残基突变为a中的甘氨酸时非常不同的行为。或珠蛋白。我们还提出了一组新的相对固定的残基作为一个参考框架，这组包含了类似数量的原子，众所周知的“BGH”框架，但显示出一个小得多的Rmsd值之间的R和T状态模型的HbA。(c)2006爱思唯尔有限公司保留所有权利。
The most recent refinement of the crystallographic structure of oxyhaemoglobin (oxyHb) was completed in 1983, and differences between this real-space refined model and later R state models have been interpreted as evidence of crystallisation artefacts, or numerous sub-states. We have refined models of deoxy, oxy and carbonmonoxy Hb to 1.25 angstrom resolution each, and compare them with other Hb structures. It is shown that the older structures reflect the software used in refinement, and many differences with newer structures are unlikely to be physiologically relevant. The improved accuracy of our models clarifies the disagreement between NMR and X-ray studies of oxyHb, the NMR experiments suggesting a hydrogen bond to exist between the distal histidine and oxygen ligand of both the alpha and beta-subunits. The high-resolution crystal structure also reveals a hydrogen bond in both subunit types, but with subtly different geometry which may explain the very different behaviour when this residue is mutated to glycine in a. or globin. We also propose a new set of relatively fixed residues to act as a frame of reference; this set contains a similar number of atoms to the well-known "BGH" frame yet shows a much smaller rmsd value between R and T state models of HbA. (c) 2006 Elsevier Ltd. All rights reserved.