付里叶变换红外光谱法研究不同条件下菌紫质的结构

FOURIER TRANSFORM INFRARED SPECTROSCOPIC STUDIES OF THE STRUCTURE BACTERIORHODOPSIN AT DIFFERENT HYDRATIONS

本文用付里叶红外光谱法研究了干燥、水合及缓冲液内菌紫质的结构.酰胺Ⅰ和Ⅱ带有多个肩峰,在不同条件下,各峰的频率无明显位移.红外光谱表明,主要为α-螺旋结构,同时含有相当比例的反平行β-束及某些无规结构.酰胺Ⅰ带吸收频率最大值计算的α_n-螺旋频率.

The structure of bacteriorhodopsin in purple membrane was investigated using fourier transform infrared spectroscoby. The samples were examined in buffer and after rehydrated over K2SO4 - saturated solution, air-and P2O5 -dried The spectra show that for all the four samples the amide I and II bands consist of a major absorption and several shoulders respectively, which suggests some proportion of β-strand, some are antiparallel in orientation, some β-turn and disordered structure besides a predominant α-helical structure. The amide I absorption frequency is dose to that calculated for αII - helical conformation. The hydrations do not change the presence of the amide I and n shoulders and their frequencies, indication that the hydrations do not affect the secondary structure of bacteriorhodopsin significantly.