A Sequence in the loop domain of hepatitis C virus E2 protein identified in silico as crucial for the selective binding to human CD81
Fig 4
MM/PBSA binding free energy calculations for human and rat CD81s to HCV E2 protein.
(A) For different HCV E2 sites (E2-site1, E2-site2, and E2-both sites) binding to human and rat CD81s, the binding free energies of human CD81 to HCV E2 were lower than those of rat CD81. HCV E2-site2 bound to human CD81 with the lowest binding free energy (H-E2-S2). (B) The detailed analysis of the components of binding free energies showed that the major difference for HCV E2-site2 binding to human and rat CD81s lies in the electrostatic interactions (H-E2-S2 and R-E2-S2). VDW dominates the binding of HCV E2-site1 to human CD81 (H-E2-S1). The figure represents the following. For H-E2-S1: the E2-site1 binding to human CD81; for H-E2-S2: the E2-site2 binding to human CD81; for H-E2-both: E2-both sites binding to human CD81; for R-E2-S1: the E2-site1 binding to rat CD81; and for R-E2-S2: the E2-site2 binding to rat CD81.