FURTHER STRUCTURAL-ANALYSIS OF THE MURINE H-2KB GLYCOPROTEIN USING RADIOCHEMICAL METHODOLOGY

This report documents progress towards determination of the complete amino acid sequence of the murine MHC† H-2 Kb molecule, using radiolabeled material obtained by immune precipitation of H-2.33 bearing glycoproteins from non-ionic detergent lysates of lymphoid tumor cells (EL4) cultured in the presence of radiolabeled amino acids. All amino acids including Gln but with the exception of aspartic acid and asparagine have been successfully incorporated in isotopically labeled form in the Kb molecule at levels sufficient to allow assignment of 153 residues in 170 positions. Automatic sequence analysis was carried out on the intact molecule, on CNBr fragments, and most recently on peptides isolated by ion exchange chromatography from tryptic digests of CNBr fragments. Analysis of our recently obtained data on the amino acid sequence of the H-2Kb antigen reveals 73% homology to human HLA molecules for the 124 positions available for comparison at this time. The majority of differences between the molecules occur within discrete regions. © 1979.