Figure 8. HCV E2 structural analysis.

(A and B) Comparative analysis of the nine HC-84 antibody epitopes and their location on a structure model of the E2 glycoprotein. Contact residues (shown in circles) are located in two discontinuous regions on E2, aa420–446 and aa613–616. Red indicates residues in domain I; black is a cysteine; and blue is residues in domain III. The specific contact residues for the HC-84 antibodies (+) span two domains (I and III) of a structural model of E2, within the central domain I the residues are located on two β-strands, C₀, and D₀. (B) Mapping of the HC-84 contact residues on the N-terminal side of the 4-stranded C₀D₀E₀F₀ β-sheet and more specifically, the C₀D₀ β-hairpin. To account for the distance between residues 420 and 428, the glycosylation site at 423–425 is shown to be bulging out and with the loop connecting the C₀ and D₀ strands having a somewhat convoluted 3-dimensional conformation. Residues 428 and 437 are brought close in space in the proposed model.