Biochemical characterization of Ia antigens. Characterization of a 22,000-dalton A delta d polypeptide expressed by I-Ad haplotype mice.
Small amounts of a 22,000-dalton (22Kd) Ia polypeptide were immunoprecipitated with monoclonal anti-Ia antibodies from murine B lymphocyte tumor cells and from splenocytes that express the I-Ad subregion. HPLC peptide map comparisons of A alpha d, A beta d and the 22Kd polypeptides demonstrated that the 22Kd polypeptide has extensive homology with A alpha d. Amino terminal sequence analysis of the 3H-tyrosine 22Kd polypeptide indicates this polypeptide has tyrosines at residues 16, 17, 30, and 32. Unexpectedly, this amino terminal 22Kd sequence is homologous with A beta d rather than A alpha d. These results suggest that the 22Kd polypeptide is a hybrid molecule containing both A alpha d and A beta d-like sequences. The 22Kd polypeptide has provisionally been designated A delta d.
D000595:Amino Acid Sequence; D000818:Animals; D055598:Chemical Phenomena; D002621:Chemistry; D002851:Chromatography, High Pressure Liquid; D005802:Genes, MHC Class II; D006238:Haploidy; D000949:Histocompatibility Antigens Class II / Q000032:analysis*; D007163:Immunosorbent Techniques; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D008970:Molecular Weight; D010447:Peptide Hydrolases / Q000235:genetics; D010455:Peptides / Q000032:analysis / Q000235:genetics / Q000276:immunology*
D000949:Histocompatibility Antigens Class II; D010455:Peptides; D010447:Peptide Hydrolases