Passamonti S, Sottocasa G L
Dipartimento di Biochimica Biofisica e Chimica delle Macromolecole, Università degli Studi di Trieste, Italy.
Biochim Biophys Acta. 1990 Jan 15;1021(1):9-12. doi: 10.1016/0005-2736(90)90376-y.
Both inactivation of sulfobromophthalein transport in rat liver plasma membrane vesicles by sulfhydryl group reagents and subsequent reactivation by 2-mercaptoethanol are shown to be modulated by ligands to bilitranslocase. In particular, bilirubin, sulfobromophthalein and Thymol blue behave as negative effectors in the inactivation reaction and as positive effectors in the reactivation reaction. Kinetic data provide further evidence of the existence of two classes of sulfhydryl groups involved in transport activity. The effect brought about by remarkably low concentrations of bilirubin is in line with the physiological function of bilitranslocase as a bilirubin carrier.
巯基试剂使大鼠肝细胞膜囊泡中的磺溴酞转运失活，随后2-巯基乙醇使其重新激活，这两个过程均受胆红素转运蛋白配体的调节。特别是，胆红素、磺溴酞和百里酚蓝在失活反应中表现为负效应物，在重新激活反应中表现为正效应物。动力学数据进一步证明了参与转运活性的两类巯基的存在。极低浓度胆红素所产生的效应与胆红素转运蛋白作为胆红素载体的生理功能是一致的。
