Cysteines 431 and 1074 are responsible for inhibitory disulfide cross-linking between the two nucleotide-binding sites in human P-glycoprotein.

@article{Urbatsch2001Cysteines4A,
  title={Cysteines 431 and 1074 are responsible for inhibitory disulfide cross-linking between the two nucleotide-binding sites in human P-glycoprotein.},
  author={Ina L. Urbatsch and Khursheed Gimi and Susan Wilke-Mounts and Nicole Lerner-Marmarosh and Mary Ellen Rousseau and Philippe Gros and Alan E. Senior},
  journal={The Journal of biological chemistry},
  year={2001},
  volume={276 29},
  pages={26980-7}
}
Human wild-type and Cys-less P-glycoproteins were expressed in Pichia pastoris and purified in high yield in detergent-soluble form. Both ran on SDS gels as a single 140-kDa band in the presence of reducing agent and showed strong verapamil-stimulated ATPase activity in the presence of added lipid. The wild type showed spontaneous formation of higher molecular mass species in the absence of reducing agent, and its ATPase was activated by dithiothreitol. Oxidation with Cu(2+) generated the same… CONTINUE READING