FTIR光谱法研究天花粉蛋白的热去折叠过程

Study on Thermal Unfolding Process of Trichosanthin by FTIR Spectroscopy

本文利用FTIR光谱技术和计算机辅助解析技术 (二阶导数、去卷积和曲线拟合 )研究了天花粉蛋白的热诱导去折叠过程。结果表明 :在 2 5～ 85℃温度范围内 ,天花粉蛋白的热去折叠是一个不可逆的分子间聚集的过程 ;二级结构随温度的变化暗示了折叠中间体的存在。

Fourier transform infared spectroscopy,combined with resolution enhancement techniques including second derivative spectroscopy,Fourier self deconvolution and curvefitting technique,was used to investigate the thermally induced unfolding process of anti HIV I toxin protein trichosanthin.During heating from 25 ℃ to 85℃,the peak of Amide I shifted to 1618 cm -1 while the secondary structural contents change with the temperature.Upon cooling the protein from 85℃ to 25℃,the contour of the Amide I do not change.All these show that the thermal unfoflding of trichosanthin is an irreversible intermolecular aggregation process between 25℃ and 85℃.The changes of secondary structures with temperature suggest the presence of folding intermediates.