稀土离子对带3蛋白阴离子转运活性及血影膜流动性的影响  

THE EFFECTS OF RARE EARTH IONS ON ANION TRANSPORT ABILITY OF BAND 3 PROTEIN AND MEMBRANE FLUIDITY OF RESEALED GHOST

作　　者：石永仲[1] 陈建文[1] 黄芬 

机构地区：[1]中国科学院生物物理所生物大分子国家重点开放实验室

出　　处：《生物物理学报》1994年第4期591-596,共6页Acta Biophysica Sinica

基　　金：国家自然科学基金

摘　　要：测定了Ｌａ２＋、Ｇｄ３＋、Ｔｂ３＋及Ｙｂ３＋四种稀土离子对带３蛋白阴离子转运活性及对血影膜脂流动性的影响。结果如下：（１）稀土离子可强烈抑制带３蛋白的阴离子转运活性，抑制程度随稀土离子浓度增加而增加，最高达到６３．７％。（２）不同的稀土离子对带３蛋白的抑制程度不同，抑制程度从大到小的顺序为Ｙｂ＞Ｔｂ＞Ｇｄ＞Ｌａ。（３）稀土离子可显著降低血影膜流动性，并且在脂双层的全部厚度内都降低，降低的程度随稀土浓度的增大而增大。（４）不同的稀土离子对血影膜流动性的影响不同，作用从大到小的顺序与它们对带３蛋白活性抑制程度大小的顺序一致。（５）稀土离子对血影膜流动性的影响特征与稀土离子抑制带３蛋白活性的特征完全相符，带３蛋白中承担阴离子转运功能的部分是贯穿性膜蛋白，并且在阴离子转运过程中要发生显著的构象变化，因此稀土离子可能是通过作用于膜脂再影响带３蛋白活性的。The effects of four rare earth ions La、 Gd、 Tb and Yb, on the anion transport ability of band 3 protein and the membrane fluidity of resealed ghost were studied. The results are as following: (1) The anion transport activity of band 3 protein is inhibited strongly by rare earth ions; in a concentration dependent way. (2) The degrea of inhibition of rare earth ions on band 3 protein Yb>Tb>Gd>La. (3) The decreased degree of membrane fluidity of resealed ghost. (4) The degree of influence of rare earth ions on membrane fluodity is in the similar to the inhibition degree of the anion transport ability. (5) We found the figure of effects of rare earth ions on membrane fluidity is similar to that of inhibition effects on band 3 protein. At the same time, we know that the domain respenside for anion transport in band 3 protein is transmebrane and performs a significant conformational change. According, the rare earth ions affect the function of band 3 protein by changing the membrane fluidity first.

关 键 词：带3蛋白 稀土离子 阴离子 转运 膜流动性 

分 类 号：Q71[生物学—分子生物学] Q73