Vaz W L, Kapitza H G, Stümpel J, Sackmann E, Jovin T M
Biochemistry. 1981 Mar 3;20(5):1392-6. doi: 10.1021/bi00508a055.
The translational diffusion of the integral membrane sialoglycoprotein from erythrocyte membranes, glycophorin, incorporated into bilayer membranes of dimyristoyl-phosphatidylcholine at a protein/lipid molar ratio of 1:4500 was examined by using the fluorescence redistribution after photobleaching technique. A plot of the diffusion coefficient vs. temperature shows a sharp decrease in the rate of diffusion at about 15 degrees C. This sharp diffusion transition is at a temperature some 9 degrees C lower than the calorimetrically measured lipid gel-liquid crystalline phase transition temperature of the system. The difference between the diffusion transition temperature and the lipid phase transition temperature is attributed toi a localized fluidizing effect of the protein upon the gel phase lipid. The value of the diffusion coefficient above 15 degrees C was found to be (1-2) x 10(-8) cm(2)s(-1), and below 15 degrees C it was lower than about 5 x 10(-11)cm(2)s(-1). The fluorescence recovery in the bleached area as a consequence of diffusional redistribution appeared to be due to a single diffusing species at temperatures above 15 degrees C and due to more than one diffusing species below this temperature.
采用光漂白后荧光重新分布技术，研究了整合膜唾液糖蛋白（红细胞膜糖蛋白）以1:4500的蛋白质/脂质摩尔比掺入二肉豆蔻酰磷脂酰胆碱双层膜后的平移扩散。扩散系数与温度的关系图显示，在约15℃时扩散速率急剧下降。这种急剧的扩散转变温度比该系统量热法测得的脂质凝胶-液晶相变温度低约9℃。扩散转变温度与脂质相变温度之间的差异归因于蛋白质对凝胶相脂质的局部流化作用。发现15℃以上的扩散系数值为(1-2)×10(-8)cm(2)s(-1)，15℃以下则低于约5×10(-11)cm(2)s(-1)。在高于15℃的温度下，由于扩散重新分布，漂白区域的荧光恢复似乎是由于单一扩散物种引起的，而在该温度以下则是由于不止一种扩散物种引起的。
