Sensitivity of rat renal luminal and contraluminal sulfate transport systems to DIDS.
Sensitivity of rat renal luminal and contraluminal sulfate transport systems to DIDS.
复制标题
大鼠肾腔和腔内硫酸盐转运系统对 DIDS 的敏感性。
DOI：
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发表时间：
1986
影响因子：
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通讯作者：
G. Burckhardt
中科院分区：
文献类型：
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作者：
C. Bästlein;G. Burckhardt
4，4‘-二异硫氰基二苯乙烯-2，2’-二磺酸(DIDS)是大鼠肾刷缘和基底侧膜囊泡硫酸盐转运系统的抑制剂。Na+驱动的硫酸盐吸收刷状缘膜囊泡在350微米直径时被半最大抑制。KI为2.4微米的DIDS竞争性地抑制质子梯度驱动的硫酸盐吸收到基侧膜囊泡。三角洲pH驱动硫酸盐吸收的Km值为5.4微米。硫酸盐转运系统对DDS的不同亲和力与底物的不同特性有关。腔转运系统接受的阴离子范围比对照系统小，并且不是作为Na+独立的阴离子交换器运行。在pH为8.4的条件下，50微米DIDS处理基底侧膜囊泡30min后，硫酸盐摄取出现不可逆转的抑制。对于刷状边界膜，只获得了很小的不可逆抑制。在pH为6.4时用DIDS处理基侧膜后没有抑制作用，表明DIDS与转运蛋白的去质子化氨基发生了反应。硫酸盐不受DIDS的不可逆抑制。钠驱动的L谷氨酸和琥珀酸甲酯摄取到基底侧膜囊泡中不能被DIDS不可逆地抑制，这表明DIDS对对侧膜硫酸盐转运系统具有特异性作用。硫酸盐转运的不可逆性和底物保护的抑制使DIDS适合于未来对基底侧膜中硫酸盐转运系统的亲和标记研究。
4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS) was tested as an inhibitor of the sulfate transport systems in rat renal brush border and basolateral membrane vesicles. Na+-driven sulfate uptake into brush border membrane vesicles was half-maximally inhibited at 350 microM DIDS. Proton gradient-driven sulfate uptake into basolateral membrane vesicles was competitively inhibited by DIDS with a Ki of 2.4 microM. The Km for delta pH-driven sulfate uptake was 5.4 microM. The different affinities of the sulfate transport systems for DIDS correlated with different substrate specificities. The luminal transport system accepted a smaller range of anions than the contraluminal system and did not operate as a Na+-independent anion exchanger. After treatment of basolateral membrane vesicles with 50 microM DIDS at pH 8.4 for 30 min, an irreversible inhibition of sulfate uptake was observed. With brush border membranes, only a small irreversible inhibition was obtained. Lack of inhibition after treatment of basolateral membranes with DIDS at pH 6.4 indicated that DIDS reacted with deprotonated amino groups of the transport protein. Sulfate was protected from the irreversible inhibition by DIDS. Sodium-driven uptake of L-glutamate and methylsuccinate into basolateral membrane vesicles was not irreversibly inhibited by DIDS, indicating a specific action of DIDS on the contraluminal sulfate transport system. Irreversible and substrate-protectable inhibition of sulfate transport render DIDS suitable for future affinity labeling studies on the sulfate transport system in basolateral membranes.