Antibodies to the autophosphorylation sites of the epidermal growth factor receptor protein-tyrosine kinase as probes of structure and function.

摘要: Abstract Antisera were prepared against three synthetic peptides with amino acid sequences identical to those surrounding the major autophosphorylation sites of epidermal growth factor (EGF) receptor. The affinity-purified antibodies reacted strongly in an enzyme-linked immunosorbent assay immunizing peptide but showed little cross-reaction other two phosphorylation site peptides. EGF receptors labelled by could be specifically precipitated each antibodies. recognised at sites, indicating that they bind irrespective their states phosphorylation. able inhibit receptor without affecting EGF-stimulated tyrosine kinase activity towards exogenous substrates, suggesting and distinct domains. Immunofluorescent staining A431 cells resided inside cell. shown within a domain 20 000 mol. wt. which cleaved from through limited proteolysis calcium-dependent protease, calpain. position cleavage protease was mapped lie between residues 996 1059. These results are discussed context model for structure function human