摘要
本文用5′酮基软脂的甲酯的N′氧基4、4-二甲基(口恶)唑衍生物、TEMPO和4-(乙氧基氟代磷酸))-TEMPO′研究了嗜盐菌紫膜的相变.ESR测定表明:在醋酸钠缓冲溶液中(100mM、pH7.0)、30至70℃没有观察到相转变;在81℃附近获得了紫膜类脂的另一相变点,此转变点可能与紫膜类脂及蛋白质晶格的分离有关.紫膜蛋白质的热变性点则在100℃附近.当温度升至110℃时紫膜类脂烃链则趋“熔化”,紫膜蛋白质的热变性也呈不可逆的.文中还就不同的物理因素对紫模相变的影响进行了讨论.
N-oxyl-4, 4- dimethyloxazolidine derivatives of the 5 - ketopalmitic methyl ester, 2, 2, 6, 6-tetramethylpipe-ridine-1 -oxyl (TEMPO) and 4-(ethoxyfiuorophosphinyloxy) -TEMPO free radicals were used to study the phase transitions of purple membrane (PM) isolated free Halobacterium halobium. ESR measurements suggested that no transition was observeded at temperature region between 30℃ and 70 ℃. In sodium acetate buffer (100mM, pH7.0), an another phase transition point of lipid of PM was seen at about 81℃ which related probably to separate change in crystalline structure between membrane protein and lipid. Thermal denaturating transition of protein of PM was detected at abiut 100 ℃. The hydrocarbon of lipid of PM was detected at about 100 ℃. The hydrocarbon of lipid of PM had 'melting' and the thermal denaturation of protein of PM was also inreversible change, when the temperature was risen to 110 ℃. In addition, the effect of phase transition of PM on different physical factor have also been discussed
出处
《生物物理学报》
CAS
CSCD
北大核心
1990年第1期100-105,共6页
Acta Biophysica Sinica
