Direct demonstration that the monoclonal antibody AMT‐13 and interleukin 2 bind to the same molecule

摘要

Abstract125I‐labeled surface molecules from mouse T lymphoblasts were fractionated by affinity supports coupled with recombinant interleukin 2 (IL2) and the monoclonal anti‐ body (mAb) AMT‐13. Sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE) analysis demonstrated that two molecules of ∼ 55 kDa and of ∼ 180 kDa were bound in both cases. Sequential precipitation and SDS‐PAGE analysis of the precipitated molecules revealed that only the ∼ 55‐kDa molecule eluted from AMT‐13 mAb support was rebound to IL2 affinity support. In addition, IL2 inhibited specifically the binding of125I‐labeled AMT‐13 mAb to T lymphoblasts. Thus the results directly demonstrate that the a ∼ 55‐kDa cell surface molecule repre‐ sents the IL2binding protein and that the mAb A