Divergent Spatiotemporal Interaction of Angiotensin Receptor Blocking Drugs with Angiotensin Type 1 Receptor

Crystal structures of the human angiotensin II type 1 receptor (AT(1)R) complex with the antihypertensive agent ZD7155 (PDB id: 4YAY) and the blood pressure medication Benicar (PDB id: 4ZUD) showed that binding poses of both antagonists are similar. This finding implies that clinically used angiotensin receptor blocking (ARB) drugs may interact in a similar fashion. However, clinically observed differences in pharmacological and therapeutic efficacies of ARBs lead to the question of whether the dynamic interactions of ATIR with ARBs vary. To address this, we performed induced-fit docking (IFD) of eight clinically used ARBs to ATIR followed by 200 ns molecular dynamic (MD) simulation. The experimental K-i values for ARBs correlated remarkably well with calculated free energy with R-2 = 0.95 and 0.70 for AT(1)R-ARB models generated respectively by IFD and MD simulation. The eight ARB ATIR complexes share a common set of binding residues. In addition, MD simulation results validated by mutagenesis data discovered distinctive spatiotemporal interactions that display unique bonding between an individual ARB and ATIR These findings provide a reasonably broader picture reconciling the structure-based observations with clinical studies reporting efficacy variations for ARBs. The unique differences unraveled for ARBs in this study will be useful for structure-based design of the next generation of more potent and selective ARBs.