Abstract

The amino-terminal 173 residues of the murine histocompatibility antigen H-2Kb have been assigned by using radiochemical methodology. The complete sequence of an 86 residue glycopeptide (CN-Ib), which is one of the five major CNBr fragments of Kb, was determined by analysis of peptides obtained from digests using thrombin and V8 staphylococcal protease. Complete sequences were obtained for the three large thrombic peptides, and these were aligned by using peptides from the V8 protease digest. Alignment of the CNBr fragments was carried out by using [35S]Met-labeled peptides from a tryptic digest of the papain-cleaved H-2Kb molecule. Positive identification was possible for all the common amino acids except Asp (Asp) which was indirectly assigned and which is designated in italics. The sequence obtained in our studies was Gly-Pro-His-Ser-Leu-Arg-Tyr-Phe-Val-Thr-Ala-Val-Ser-Arg-Pro-Gly-Leu-Gly-Glu-Pro-Arg-Tyr-Met-Glu-Val-Gly-Tyr-Val-Asp-Asp-Thr-Glu-Phe-Val-Arg-Phe-Asp-Ser-Asp-Ala-Glu-Asn-Pro-Arg-Tyr-Glu-Pro-Arg-Ala-Arg-Trp-Met-Glu-Gln-Glu-Gly-Pro-Glu-Tyr-Trp-Glu-Arg-Glu-Thr-Gln-Lys-Ala-Lys-Gly-Asn-Glu-Gln-Ser-Phe-Arg-Val-Asp-Leu-Arg-Thr-Leu-Leu-Gly-Tyr-Tyr-(Asn)-Gln-Ser-Lys-Gly-Gly-Ser-His-Thr-Ile-Gln-Val-Ile-Ser-Gly-Cys-Glu-Val-Gly-Ser-Asp-Gly-Arg-Leu-Leu-Arg-Gly-Tyr-Gln-Gln-Tyr-Ala-Tyr-Asp-Gly-Cys-Asp-Tyr-Ile-Ala-Leu-Asn-Glu-Asp-Leu-Lys-Thr-Trp-Thr-Ala-Ala-Asp-Met-Ala-Ala-Leu-Ile-Thr-Lys-His-Lys-Trp-Glu-Gln-Ala-Gly-Glu-Ala-Glu-Arg-Leu-Arg-Ala-Tyr-Leu-Glu-Gly-Thr-Cys-Val-Glu-Trp-Leu-Arg-Arg-Tyr-Leu-Lys. These data represent the longest reported amino acid sequence determined by utilizing radiochemical methodology and provide the first extensive information on the primary structure of murine histocompatibility antigens.