带3蛋白6种跨膜截断体阴离子转运功能的研究

目的 探寻带3蛋白膜段域不同跨膜片段在带3蛋白离子转运过程中的作用。方法 构建编码带3蛋白膜段域片段的重组质粒，将其转入酵母细胞诱导表达，并以蛋白免疫印记及荧光探针的方法检测目的蛋白。结果 拥有前10个跨膜α螺旋的带3蛋白片段TM1—10具有氯离子转运活性，而TM1-8，TM1-9则完全失去功能。此外，删除C末端后16个氨基酸的带3蛋白膜段域片段功能与拥有全长膜段域的带3蛋白相仿。结论 TM10在带3蛋白离子转运功能中发挥重要作用。

Study of anion transport activity of six transmembrane fragments of band 3

Objective To clarify the anion transport activity of six transmembrane segments of band 3.Methods The recombinant plasmids pYD1 encoding various portions of the human red cell band 3 were constructed, and the functionality of these band 3 segments were investigated by the yeast display expression system. The expressions of band 3 fragments were certified by dot blot analysis.Results Expressions of recombinants encoding the first 10 transmembrane (TM) spans of band 3 generated DIDS sensitive anion transport activity in yeast cells, but expressions of TM1 8 or TM1 9 didn't generate anion transport activity. Moreover, a truncated form of band 3 encoding all 14 transmembrane spans but lacking the carboxyl terminal 16 amino acids of the cytoplasmic tail induced anion transport activity similar to full length membrane domain of band 3 in yeast cells.Conclusion The TM10 is a important segment to anion transport of band 3.