【摘要】 本文报道了pH7.5时血红蛋白和红细胞膜的结合效应.在10—45℃温度范围内观察到血红蛋白对膜脂质流动性的限制作用.看来这种限制作用不是脂质过氧化所致,而是血红蛋白和红细胞膜直接作用的结果.对流动性大的膜,血红蛋白的效应也随之增大.高铁血红蛋白及红细胞膜去胆固醇皆能修饰血红蛋白和膜的相互作用.更多还原

【Abstract】 The interaction of Hb with the erythrocyte membrane is certainly present at physiological pH. The conversion of HbO2 into MetHb or membrane depletion of cholesterol can modify Hb-membrane binding.MetHb has strong interaction with the erythrocyte membrane; in contrast, cholesterol depletion decreases Hb binding to membrane. With fluorescence polarization and spin label ESR techniques, the effect of Hb on the membrane fluidity was detected. It was found that there was a significant restriction of membrane lipid molecular dynamics at pH 6 by Hb. The restriction was increased with temperatures and was much stronger at the core of the biomolecular membrane than at the surface. Although an amount of Hb binding to cholesterol-depleted erythrocyte membrane was decreased, but the effect of Hb on membrane fluidity was more serious. It was suggested that the restriction of membrane fluidity by Hb-membrane interaction would be more effective when the erythrocyte membrane was in more fluid state. On the other hand, a structure change of Hb also affects membrane fluidity. The spin label experiment showed that membrane fluidity at pH 7.5 might be more sensitive to MetHb than HbO2.It seems that the restriction of membrane fluidity was caused by direct interaction of Hb with membrane lipids, and no evidence was found for significant lipid peroxidation in our experiments. The study of interaction of Hb with the erythrocyte membrane could provide information on the interaction of cytoplasmic protein with biomembrane in the eucaryotic cells.更多还原