Computational and structural insights into the pre- and post-hydrolysis states of bovine multidrug resistance associated protein 1 (MRP1)

Abstract

ABC C-family drug membrane transporters play an important role in local pharmacokinetics, i.e., drug concentration in cellular compartments. From the structural point of view, only the bovine ortholog of the multidrug-resistance associated protein 1 have been resolved. We here used microsecond-scaled MD simulations to investigate the structure and dynamics of bMRP1 in pre- and post-hydrolysis functional states. The present work aims to investigate the slight but likely relevant structural differences between pre- and post-hydrolysis states of OF conformations as well as the interactions between MRP1 and surrounding lipid molecules. Global conformational dynamics show unfavourable extracellular opening associated with NBD dimerization indicating that the post-hydrolysis state adopts a close-conformation rather than an outward-open conformation. Our present MD simulations also strengthen the expected active role of surrounding lipid in the allosteric communication between distant domain of MRP1 transporter. Furthermore, PE lipids in the inner leaflet as well as cholesterol in the so-called Cholesterol recognition amino acid consensus (CRAC) or inverted (CARC) motifs are expected to be key in MRP1 function.