p56lck is a T cell-specific protein tyrosine kinase of the src family of proto-oncogenes which has been implicated in T cell signal transduction. Here we describe the production of mouse monoclonal antibodies directed against recombinant human p56lck purified from an E. coli expression system. The antibodies were characterized by ELISA, RIA and immunoprecipitation of p56lck from T cell lysates. A specific epitope was revealed at the aminoterminus of the p56lck molecule by using Western blotting of deletion mutants and distinct domains of p56lck expressed in E. coli. Potential applications of the results obtained are discussed.
