细胞色素b5稳定性的光谱学研究

Study on Stability of Cytochrome b5 by Spectroscopic Techniques

利用圆二色光谱和荧光光谱法研究细胞色素b5蛋白在温度和酸度变化过程中蛋白质构象的情况。发现在升高温度和降低pH值的情况下,细胞色素b5蛋白的荧光吸收峰均有下降的趋势,表明色氨酸残基环境的极性增加而疏水性降低,细胞色素b5内部的疏水结构有所瓦解,构象发生改变。升高温度时,圆二色谱的谱图中α-helix含量下降,说明细胞色素b5的二级结构发生变化,稳定性降低。外部条件的改变,可使细胞色素b5的构象发生变化,分子内部极性增强,α-螺旋含量下降。

It is a focus for scholars in biology and chemistry field to research biomacromolecules＇ change of structure and function.The configuration change has been studied in different temperature and Ph by the fluorescence spectrum and circular dichroism spectra.It is showed that the peak intensity of the cytochrome b5 decrease with increasing the temperature or cutting down the pH.It shows that the polarity in the environment of tryptophan residues has increased and the hydrophobic has been reduced.The hydrophobic region in the interior of cytochrome b5 has been collapsed,and the conformation is changed.At the same time, the a-helix content decreased in the spectrogram of circular dichroism spectra with temperature increasing, which shows the secondary structure of the cytochrome b5 has been changed and the stability diminished. When the extra conditions are changed,such as temperature and pH,the configuration,polarity and a-helix content have been changed.