Rat cell surface antigens. I. Isolation and partial characterization of an Ag-B antigen.

Rat major histocompatibility or Ag-B antigen was isolated from soluble extracts of lymphoid cells by affinity chromatography. The purified antigen was shown in SDS gel electrophoresis to have a molecular weight of 30,000 to 35,000 daltons. In addition, amino acid composition was found to resemble, generally, that of HL-A and H-2 antigens. It thus appears that the demonstrated homology between H-2 and HL-A extends also to Ag-B.