Characterization of cytomegalovirus glycoproteins in a family of complexes designated gC-II with murine monoclonal antibodies.

Several murine monoclonal antibodies (MoAbs) were made to a family of human cytomegalovirus (HCMV) disulfide linked glycoprotein complexes designated gC-II. Characterization of these MoAbs by immunological methods showed that they could be divided into two groups recognizing different glycoproteins. Western blot analysis was done with immunoaffinity purified gC-II complexes. Under non-reducing conditions MoAbs from both groups recognized gC-II complexes with molecular weights of 67-93 k and 130 k to greater than 200 k. When purified gC-II complexes were reduced and individual glycoproteins separated by SDS-PAGE prior to Western blotting, Group 1 MoAbs reacted with glycoproteins having molecular weights of 47-63k, while Group 2 MoAbs reacted with glycoproteins having molecular weights of 39-48k and 90k to greater than 200k. Thus, gC-II complexes contain glycoproteins recognized by both groups of MoAbs. By Coomassie blue staining and incorporation of [3H]Arg, Group 1 glycoproteins appeared to be minor components in the complexes relative to Group 2 glycoproteins. Surface labeling of extracellular virus with galactose oxidase and tritiated borohydride showed that gC-II complexes of all molecular weights were on the surface of the virus. However, the most heavily labeled gC-II glycoproteins had molecular weights of 47-63k. These data confirm our previous observations that the gC-II complexes of HCMV are comprised of a heterogeneous family of glycoproteins.