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 6
SPR measurements for the interactions between peptides derived from HCV E2 and CD81s.
(A) SPR responses when HCV p_E2-site1 peptide in various concentrations was flowed over the immobilized human CD81 peptide (left). The equilibrium KD of 7.96 ± 1.7 μM for p_E2-site1 binding to human CD81 peptide was determined by steady-state interaction isotherm (right). (B) SPR responses measured when p_E2-site1 in various concentrations was tested on rat CD81 peptide (left). The equilibrium KD of 13.85 ± 2.46 μM for the p_E2-site1 binding to rat CD81 peptide was given by the binding isotherm (right). (C) SPR response when peptide p_E2-site2 in different concentrations was flowed over the immobilized human CD81 peptide (left). The binding isotherm gives the equilibrium KD of 1.07 ± 0.09 μM for p_E2-site2 binding to human CD81 peptide (right). (D) SPR responses when peptide p_E2-site2 in various concentrations was tested on rat CD81 peptide. The response only increased slightly as the concentration of the peptide increased (left). The equilibrium KD of 6.38 ± 0.58 μM for the p_E2-site2 binding to rat CD81 peptide was calculated from the steady-state binding isotherm (right). The KD values shown are the averages of three measurements. Errors for KD are standard deviations.