人红细胞膜带3蛋白重组人脂质体及其~(35)SO_4~(2-)运输活性

用Triton X-100选择性抽提法,部分提纯了人红细胞膜带3蛋白。在除去去污剂后,带3蛋白被插入由磷脂酰胆碱/胆固醇组成的脂质体中。研究表明,用0.05％Triton抽提膜能除去大部分唾液酸糖蛋白,不会损失太多的带3蛋白。再用0.5％Triton抽提,可增溶出大量带3蛋白和少量其它膜蛋白。把它重组入脂质体后,在最后超离心步骤中得到了小的单层囊泡和大的多层囊泡。本文研究了单层重组囊泡输入~(35)SO_4~(2-)的功能,并和那些由人红细胞“发芽”得到的天然囊泡输入~(35)SO_肋~(2-)的功能作了比较。

RECONSTITUTION OF BAND 3 PROTEIN DERIVED FROM HUMAN RED CELLS INTO LIPOSOMES AND ITS ~(35)SO_4~(2-) TRANSPORT ACTIVITY

Band 3 protein of human red cell membranes was partially purified by means of a selective extraction procedure with Triton X-100.After the removal of the detergent,Band 3 were incorporated into liposomes composed of phosphatidylcho-line/cholesterol.The present work showed that the extraction with 0.05% Triton removed most of the sialoglycoproteins from the membrane,but no appreciable amount of Band 3 was extracted.Extraction with 0.5% Triton solubilized Band 3,but small amounts of other proteins,mainly from Band 4.2 and Band 4 5 region,and some previously unextracted sialoglycoproteins were found.After the final supercentrifugation step,two types of Band 3-lipid vesicles,small single-walled and large multi-walled vesicles,were obteined.In the present work,a number of 35SO42-influx function of the single-walled vesicles were studied and compared with those of the native vesicles which were obtained by 'budding' from the intact human erythrocytes.