Multiple flavonoid-binding sites within multidrug resistance protein MRP1.
Multiple flavonoid-binding sites within multidrug resistance protein MRP1.
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多药耐药蛋白 MRP1 内有多个类黄酮结合位点。
DOI：
10.1007/s00018-003-3177-6
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发表时间：
2003
期刊：
影响因子：
--
通讯作者：
DiPietro,A
中科院分区：
文献类型：
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作者：
Trompier,D;Baubichon-Cortay,H;Chang,X-B;Maitrejean,M;Barron,D;Riordon,JR;DiPietro,A
重组核苷酸结合域（NBD）从人多药耐药蛋白MRP 1在细菌中过表达和纯化，以测量其与高亲和力黄酮类化合物的直接相互作用，并评估与抑制MRP 1介导的转运活性和逆转细胞多药耐药的潜在相关性。在不同类别的黄酮类化合物中，脱氢水飞蓟宾对两种NBD都表现出最高的亲和力，与N-末端NBD 1的结合被ATP阻止。脱水水飞蓟宾增加钒酸盐诱导的8-N3-[α-32 P]ADP捕获，表明对ATP酶活性的刺激。与此相反，脱氢水飞蓟宾强烈抑制白三烯C4（LTC 4）从MRP 1转染细胞的膜囊泡运输，独立于还原型谷胱甘肽，和长春新碱的化学增敏细胞生长。脱水水飞蓟宾的疏水C-异戊二烯化使其与NBD 1的结合亲和力增加，但位于ATP位点之外，降低了钒酸诱导的8-N3-[α-32 P]ADP捕获的增加，减弱了对LTC 4转运的抑制，使其成为谷胱甘肽依赖性的，并诱导了一定的交叉抗性。总体结果表明，多个结合位点脱氢水飞蓟宾及其衍生物，在胞质和跨膜结构域的MRP 1。
Recombinant nucleotide-binding domains (NBDs) from human multidrug resistance protein MRP1 were overexpressed in bacteria and purified to measure their direct interaction with high-affinity flavonoids, and to evaluate a potential correlation with inhibition of MRP1-mediated transport activity and reversion of cellular multidrug resistance. Among different classes of flavonoids, dehydrosilybin exhibited the highest affinity for both NBDs, the binding to N-terminal NBD1 being prevented by ATP. Dehydrosilybin increased vanadate-induced 8-N3-[α-32P]ADP trapping, indicating stimulation of ATPase activity. In contrast, dehydrosilybin strongly inhibited leukotriene C4(LTC4) transport by membrane vesicles from MRP1-transfected cells, independently of reduced glutathione, and chemosensitized cell growth to vincristine. Hydrophobic C-isoprenylation of dehydrosilybin increased the binding affinity for NBD1, but outsite the ATP site, lowered the increase in vanadate-induced 8-N3-[α-32P]ADP trapping, weakened inhibition of LTC4transport which became glutathione dependent, and induced some cross-resistance. The overall results indicate multiple binding sites for dehydrosilybin and its derivatives, on both cytosolic and transmembrane domains of MRP1.