Mossbauer spectroscopic evidence on the heme binding to the proximal histidine in unfolded carbonmonoxy myoglobin by guanidine hydrochloride

被引：2

作者：

Harami, Taikan ^{[1
]}

Kitao, Shinji ^{[2
]}

Kobayashi, Yasuhiro ^{[2
]}

Mitsui, Takaya ^{[1
]}

机构：

[1] Japan Atom Energy Agcy, Sayo, Hyogo 6795148, Japan

[2] Kyoto Univ, Inst Res Reactor, Osaka 5900494, Japan

来源：

HYPERFINE INTERACTIONS | 2008年 / 181卷 / 1-3期

关键词：

Carbonmonoxy myoglobin; Unfolding; Guanidine hydrochloride; Mossbauer spectroscopy; Isomer shift;

D O I：

10.1007/s10751-008-9711-z

中图分类号：

O64 [物理化学（理论化学）、化学物理学]; O56 [分子物理学、原子物理学];

学科分类号：

070203 ; 070304 ; 081704 ; 1406 ;

摘要：

The unfolded heme structure in myoglobin is controversial because of no chance of direct X-ray structure analyses. The unfolding of carbonmonoxy myoglobin (MbCO) by guanidine hydrochloride (GdnHCl) was studied by the Mossbauer spectroscopy. The spectra show the presence of a sort of spectrum in the unfolded MbCO, independent on the concentration of GdnHCl from 1 to 6 M and the increase of the fraction of unfolded MbCO, depending on the GdnHCl concentration. The isomer shift of the iron of heme in the unfolded MbCO was identified to be different from that of the native MbCO as the globin structure in Mb collapses under the unfolded conditions. This result and the existing related Mossbauer data proved that the heme in the unfolded MbCO may remain coordinated to the proximal histidine.

引用

页码：179 / 187

页数：9

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