Comparative Chemical Analyses and Partial Amino Acid Sequences of the Heavy Chains of HL-A Antigens
- *Laboratory of Cell Biology, National Cancer Institute and §Molecular Diseases Branch, National Heart and Lung Institute, National Institutes of Health, Bethesda, Maryland 20014; †Department of Immunology Research, Roswell Park Memorial Institute, Buffalo, New York 14263; ‡American Red Cross Blood Research Laboratory, Bethesda, Maryland 20014
This extract was created in the absence of an abstract.
Excerpt
The human HL-A histocompatibility antigens are membrane glycoproteins which belong to the major histocompatibility locus. The proteins are composed of two polypeptide chains: one, with a molecular weight of approximately 45,000, that carries the alloantigenic specificities; and the other, β2-microglobulin, with a molecular weight of 11,500 (Nakamuro et al. 1973). Although HL-A antigens are highly polymorphic, structural studies have so far revealed only a very limited degree of heterogeneity (Terhorst et al. 1976; Henriksen et al. 1976; Appella et al. 1976).
We have compared several structural parameters of two papain-solubilized HL-A antigen preparations, both isolated from the human lymphoid cell line RPMI 1788 (Miyakawa et al. 1971). The heavy chains obtained from the two preparations carried the allospecificities A2 and B7,14, respectively, and were thus partially different from the antigens studied by other investigators (Terhorst et al. 1976). The total carbohydrate content of the heavy chain was 12.9%; the individual...
