Further characterization of a human T lymphocyte associated antigen.

A human T lymphocyte associated antigen (TLAA), defined with appropriately absorbed antisera to the lymphoblastoid cell line HSB, was originally characterized as a 150,000 mol. wt antigen using sodium deoxycholate solubilized, 125I Bolton-Hunter labelled membranes of HSB, thymus and peripheral blood lymphocytes. The TLAA, which appears to be the major membrane protein labelled with either the Bolton-Hunter, or galactose oxidase-sodium 3H borohydride methods, is weakly labelled in vitro with a 3H amino acid mixture and appears to be a minor membrane component by Coomassie blue staining of detergent solubilized HSB membranes. The antigen is trypsin-sensitive and not extractable with 3 M KCl. The glycoprotein nature of the antigen is suggested by its binding to a Lens culinaris column and its labelling by the galactose oxidase-sodium 3H borohydride and 3H glucosamine methods. Both gel filtration chromatography and sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis studies on 4% SDS gels indicate that the mol. wt. of the antigen is approximately 170,000 Daltons.