Soleimani M, Bizal G L, Anderson C C
Department of Medicine, Indiana University School of Medicine, Indianapolis.
Kidney Int. 1993 Sep;44(3):565-73. doi: 10.1038/ki.1993.282.
One important mechanism for reabsorption of chloride in the kidney proximal tubule involves anion exchange of chloride for a base. Anion exchange transport systems in general demonstrate sensitivity to inhibition by disulfonic stilbenes, probenecid, furosemide, and the arginyl amino group modifier phenylglyoxal. Using disulfonic stilbene affinity chromatography, we have identified and partially purified a protein with anion exchanger properties in luminal membrane vesicles isolated from rabbit kidney cortex. This protein has a molecular weight of 162 kD. The binding of the 162 kD protein to the stilbene affinity matrix is inhibited by disulfonic stilbenes, probenecid, furosemide, and phenylglyoxal. Reconstitution of the proteins eluted from the affinity matrix into liposomes demonstrates anion exchange activity as assayed by radiolabeled chloride influx. Deletion of the 162 kD protein from the eluted mixture by probenecid diminishes the anion exchanger activity in the reconstituted liposomes. Further purification of the disulfonic stilbene column eluant by Econo-Pac Q ion exchange chromatography resulted in significant enrichment in 162 kD protein abundance and also anion exchange activity in reconstituted liposomes. The results of the above experiments strongly suggest that the 162 kD protein is an anion exchanger. Insight into the functional and molecular characteristics of this protein should provide important information about the mechanism(s) of chloride reabsorption in the kidney proximal tubule.
肾脏近端小管中氯离子重吸收的一个重要机制涉及氯离子与一种碱基的阴离子交换。一般来说，阴离子交换转运系统对二磺酸芪、丙磺舒、呋塞米和精氨酰氨基修饰剂苯乙二醛的抑制敏感。利用二磺酸芪亲和层析，我们在从兔肾皮质分离的管腔膜囊泡中鉴定并部分纯化了一种具有阴离子交换特性的蛋白质。这种蛋白质的分子量为162kD。二磺酸芪、丙磺舒、呋塞米和苯乙二醛可抑制162kD蛋白质与芪亲和基质的结合。将从亲和基质洗脱的蛋白质重组到脂质体中，通过放射性标记的氯离子内流测定显示出阴离子交换活性。丙磺舒从洗脱混合物中去除162kD蛋白质会降低重组脂质体中的阴离子交换活性。通过Econo-Pac Q离子交换层析进一步纯化二磺酸芪柱洗脱液，导致162kD蛋白质丰度显著富集，重组脂质体中的阴离子交换活性也显著提高。上述实验结果强烈表明，162kD蛋白质是一种阴离子交换剂。深入了解该蛋白质的功能和分子特征应能提供有关肾脏近端小管中氯离子重吸收机制的重要信息。
