低温下肌红蛋白的重组。傅里叶变换红外光谱揭示的两个阶段。

Myoglobin recombination at low temperature. Two phases revealed by Fourier transform infrared spectroscopy.

作者信息

Chance M R, Campbell B F, Hoover R, Friedman J M

出版信息

J Biol Chem. 1987 May 25;262(15):6959-61.

Abstract

The low-temperature recombination of CO with myoglobin was studied using Fourier transform infrared spectroscopy. The bound state of carbon monoxide myoglobin has two distinct conformers observed at 1926 and 1945 cm-1 with an intensity ratio of 1 to 8. The recombination of these bands after complete photolysis at 10 K followed by a temperature jump shows distinct kinetics for the two bands. Although both bands apparently follow the nonexponential kinetics originally described by Frauenfelder and co-workers (Austin, R., Beeson, K., Eisenstein, L., Frauenfelder, H., and Gunsalus, I. (1975) Biochemistry 14, 5355-5373), the 1926 cm-1 band does not appear appreciably below 70 K. In fact, after 20 min of recombination at 70 K the 1945 cm-1 band is fully recovered, while no detectable amount of the 1926 cm-1 band is present. This is the first association of a spectroscopic marker of protein substructure with reaction kinetics.

摘要

利用傅里叶变换红外光谱研究了一氧化碳与肌红蛋白的低温重组。一氧化碳肌红蛋白的结合态有两种不同的构象体，在1926和1945 cm-1处观察到，强度比为1比8。在10 K下完全光解后进行温度跃升，这两个谱带的重组显示出不同的动力学。尽管两个谱带显然都遵循弗劳恩费尔德及其同事最初描述的非指数动力学（奥斯汀，R.，比森，K.，艾森斯坦，L.，弗劳恩费尔德，H.，和冈萨卢斯，I.（1975年）《生物化学》14，5355 - 5373），但1926 cm-1的谱带在70 K以下明显不出现。事实上，在70 K下重组20分钟后，1945 cm-1的谱带完全恢复，而1926 cm-1的谱带没有可检测到的量。这是蛋白质亚结构的光谱标记与反应动力学的首次关联。