Partial characterization of the putative rat interleukin 2 receptor.

T lymphoblasts of rat origin were (a) surface labeled with 125I and (b) internally labeled with 3H-marked sugars. Cell lysates were purified by immunoabsorption using the putative anti-rat interleukin 2 (IL2) receptor monoclonal antibody ART18 . The purified material was subjected to sodium dodecyl sulfate polyacrylamide gel electrophoretic analysis. Two specific membrane components were detected: a 50-kDa major and a 36-kDa minor component in reducing and a 45-kDA major and a 72-kDa minor component in nonreducing conditions, respectively. Both components were found to be susceptible to trypsinization and to neuraminidase treatment. 3H-labeled sugars were incorporated into the major component. The results indicate that the rat IL2 receptor is either a 50-kDa glycoprotein or a 36-kDa molecule, or that both components are part of the receptor molecule.