Phase transitions of the purple membrane and the brown holo-membrane X-ray diffraction, circular dichroism spectrum and absorption spectrum studies

摘要: Abstract The phase transition of the purple membrane observed by differential scanning calorimetry (Jackson, M.B. and Sturtevant, J.M. (1978) Biochemistry 17, 911–915) has been investigated X-ray diffraction, circular dichroism absorption spectrum, in comparison with brown holo-membrane. two-dimensional crystal bacteriorhodopsin transformed into liquid around 74–78°C 50–60°C diffraction patterns obtained at 78°C for 60°C holo-membrane exhibit several broad peaks. Analysis pattern suggests that molecules aggregate trimers even above temperature. negative band visible region is still present 80°C holo-membrane, but becomes negligibly small 70°C 560 nm peak due to changes its position height drastically as membrane. studies have made on membranes total lipids extracted from No indication found between −81°C 77°C.