Type-specific reactivity of anti-glycoprotein G antibodies from herpes simplex virus-infected individuals is maintained by single or dual type-specific residues

Glycoprotein G-1 (gG-1) of herpes simplex virus type 1 (HSV-1) and gG-2 of HSV-2 are the only known HSV proteins that induce type-specific human antibody responses. Recently, it was shown that purified human anti-gG-1 and anti-gG-2 antibodies presented a type-specific reactivity to immunogenic stretches with high similarity between gG-1 and gG-2. In this study, the molecular basis for this type-specific recognition was investigated employing synthetic peptides covering the indicated regions, including substitutions of the type-specific residues. The results revealed that single or dual type-specific residues localized within regions of high similarity could induce significant structural differences, explaining the type-specific recognition of the human antibody response to the gG proteins.