The region of the murine 17th chromosome telomeric to H-2D encodes a group of serologically defined cell surface antigens termed Qa-1-5. These antigens are of interest because their expression is restricted to hematopoietic cells. In addition, the molecular weight and subunit structure (ie, association with β-2 microglobulin) of Qa-2 molecules are similar to H-2 and TL antigens. In the present studies, we have prepared isotopically labeled Qa-2 and H-2 molecules from mitogen-stimulated C57BL/6 spleen cells. Comparative peptide mapping of tryptic peptides from Qa-2 and H-2 molecules (K(b), D(b)K(k), D(d)) reveal that Qa-2 has a unique primary structure. However, considerable homology is indicated since 30-40% of the Qa-2 peptides cochromatograph with peptides derived from H-2K(b), H-2D(b), H-2K(k), and H-2D(d). Studies by other investigators have demonstrated that similar levels of structural homology are observed when H-2K, H-2D, and H-2L tryptic peptides are analyzed. We conclude from these studies that the Qa-2 alloantigen is structurally related to a class of cell surface molecules (ie, H-2) that play critical roles in immune recognition processes. These data further suggest that the genes encoding Qa-2 and H-2 molecules have arisen from a common primordial gene.
|Original language||English (US)|
|Number of pages||11|
|Journal||Journal of Supramolecular and Cellular Biochemistry|
|State||Published - 1981|
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