Synthetic peptide substrates for a tyrosine protein kinase.

摘要: Immunoprecipitates containing the transforming protein of avian sarcoma virus, Y73, together with its associated tyrosine-specific kinase, have an activity which will phosphorylate synthetic peptide Lys-Leu-Ile-Glu-Asp-Asn-Glu-Tyr-Thr-Ala-Arg at tyrosine residue. This corresponds to 10 out 11 amino acids surrounding phosphorylated in both pp60src and P90, proteins Rous virus Y73 respectively. The apparent Km for phosphorylation was about 5 mM. A second sequence Lys-Leu-Ile-Asp-Asn-Glu-Tyr-Thr-ala-Arg differing from first only by absence glutamic acid 4 residues also phosphorylated, but reaction 40 Several sites viral been found one or more close on NH2-terminal side. Taken our vitro studies, this suggests that primary target tyrosines may play a role recognition substrates kinases, particular, side be important.