Anticancer Drug Binding Sites in MRP1 Protein

Where are the anticancer drug binding sites in MRP1 protein? In order to define anticancer drug binding sites, we have made couple cysless MRP1 constructs (mutated all 25 cysteine residues to alanines), either full length or N-proximal half plus C-proximal half, and expressed in sf21 cells. We also made antibodies against MRP1 N-half or C-half. The cysless MRP1 protein is partially functional (to transport its substrate). Cysteine residues were introduced into the cysless MRP1 protein at the desired sites and will be utilized to screen anticancer drug binding sites by labeling with 14C-labeled N-ethylmaleimide.