The UV VIS spectra showed that BR was totally denatured and lost its retinal under the pH 12 6. It was found by atom force microscope that the crystalline lattice of purple membrane was broken down at this pH.

• 紫外可见光谱实验发现 ,当pH上升到 12 6 ,BR分子上的生色团视黄醛脱落 ,分子完全变性 ;