Major attachment protein that mediates binding of the virus to cell surface heparan sulfate or chondroitin sulfate. Also plays several roles in host immune evasion by inhibiting the host complement cascade activation, and by providing a shield against neutralizing antibodies that interfere with gB-gD, gB-gH/gL or gD-gH/gL interactions (By similarity). Interacts with host complement component C3b; this interaction inhibits host immune response by disregulating complement cascade. There are seven external glycoproteins in HSV-1 and 2: gH, gB, gC, gG, gD, gI, and gE. Membrane-bound gC. Secreted. Belongs to the herpesviridae glycoprotein C family.