Isolation and properties of detergent-solubilized HLA antigens obtained from platelets.
Deoxycholate-solubilized HLA antigens have been isolated from platelets and comprised a mixture of 43,000- and 39,000-dalton polypeptide chains associated with beta2-microglobulin. Limited proteolysis experiments suggested that the 39,000-dalton chain is a fragment of the intact 43,000-dalton chain. Further proteolysis of the 39,000-dalton fragment yields a 33,000-dalton component. The 39,000-dalton molecule is more acidic than both the 43,000- and the 33,000-dalton chains. Differences in the amino acid compositions of the 43,000- and 39,000-dalton species demonstrate that the peptide(s) released on generation of the 39,000-dalton component are charged. The proteolytic split most probably occurs in the COOH-terminal end, which, owing to its content of charged amino acids, most probably is not integrated into the hydrocarbon matrix of the membrane. The 39,000- and 43,000-dalton components bind detergent in micellar form and can be incorporated into liposomes. The 33,000-dalton fragment has lost the ability to bind detergent micelles and is not incorporated into liposomes.
D000596:Amino Acids / Q000032:analysis; D001792:Blood Platelets / Q000276:immunology*; D002241:Carbohydrates / Q000032:analysis; D002846:Chromatography, Affinity; D003840:Deoxycholic Acid / Q000494:pharmacology; D003902:Detergents / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D000939:Epitopes; D006680:HLA Antigens / Q000032:analysis / Q000302:isolation & purification*; D006801:Humans; D005779:Immunodiffusion; D007525:Isoelectric Focusing; D050356:Lipid Metabolism; D008970:Molecular Weight
D000596:Amino Acids; D002241:Carbohydrates; D003902:Detergents; D000939:Epitopes; D006680:HLA Antigens; D003840:Deoxycholic Acid