Metastable CO binding sites in the photoproduct of a novel cooperative dimeric hemoglobin.
Metastable CO binding sites in the photoproduct of a novel cooperative dimeric hemoglobin.
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新型协同二聚血红蛋白的光产物中的亚稳态CO结合位点。
DOI：
10.1016/s0006-3495(93)81267-0
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发表时间：
1993
影响因子：
3.4
通讯作者：
Chiancone,E
中科院分区：
文献类型：
--
作者：
Song,S;Rothberg,L;Rousseau,DL;Boffi,A;Chiancone,E
在10 K时，来自Scapharca inaequalivalvis血红蛋白（Hbl）的CO光产物的红外吸收光谱在2132 cm-1处的“B”状态区域中仅产生单线。这与在光解离脊椎动物HbCO和MbCO中观察到的B1线频率相同。在脊椎动物血红蛋白和肌红蛋白2118-2120 cm-1区域中未发现B2线的证据。这些数据表明，该蛋白质不具有相同的构象可及的配体结合位点，脊椎动物血红蛋白和肌红蛋白。B2线的缺乏表明，只有一个单一的弱网站是可访问的光解CO分子。这些结果雅阁与双生再结合实验和配体逃逸途径的计算表明，Hbl的远端性质是不同于那些的四聚体血红蛋白和脊椎动物肌红蛋白。
The infrared absorption spectrum of the CO-photoproduct from Scapharca inaequivalvis hemoglobin (Hbl) at 10 K yields only a single line in the "B" state region at 2132 cm-1. This is the same frequency as the B1 line observed in photodissociated vertebrate HbCO and MbCO. No evidence was found for the B2 line detected in vertebrate hemoglobins and myoglobin in the 2118–2120 cm-1 region. These data demonstrate that the protein does not have the same conformationally accessible ligand-binding sites as do vertebrate hemoglobins and myoglobins. The absence of the B2 line indicates that only a single weak site is accessible to the photolyzed CO molecule. These results are in accord with geminate rebinding experiments and ligand escape pathway calculations which have shown that the distal properties of Hbl are distinct from those of tetrameric hemoglobins and vertebrate myoglobins.