Solution 1H NMR characterization of equilibrium heme orientational disorder with functional consequences in mouse neuroglobin
Solution 1H NMR characterization of equilibrium heme orientational disorder with functional consequences in mouse neuroglobin
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DOI：
10.1021/ja034584r
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发表时间：
2003-07-09
影响因子：
15
通讯作者：
La Mar, GN
中科院分区：
文献类型：
--
作者：
Du, WH;Syvitski, R;La Mar, GN
氧化的（met）小鼠神经红蛋白，metNgb的solution1H NMR光谱表明，它是低自旋和六配位的，与ferricytochromeb 5具有很强的光谱相似性。轴向配体被鉴定为His（F8）和His（E7），后者显示出无张力的Fe−His键。两组共振的存在下，所示产生的平衡血红素取向异构体（102：1）。氰化物的连接被证明是非常缓慢的，两个血红素方向的速率差异为10.2倍。Ngb不仅是第一个具有平衡血红素障碍的哺乳动物球蛋白，而且这种障碍还具有额外的功能后果。
The solution1H NMR spectrum of oxidized (met) mouse neuroglobin, metNgb, demonstrates that it is low-spin and hexacoordinate with strong spectral similarities to ferricytochromeb5. The axial ligands are identified as His(F8) and His(E7), with the latter exhibiting an unstrained Fe−His bond. The presence of two sets of resonances is shown to arise from equilibrium heme orientational isomers (∼2:1). The ligation of cyanide is shown to be extraordinarily slow with a factor ∼2 difference in rate for the two heme orientations. Not only is Ngb the first mamalian globin with equilibrium heme disorder, but the disorder also has additional functional consequences.