Phosphorylation of synthetic peptides by a tyrosine protein kinase from the particulate fraction of a lymphoma cell line

摘要: Abstract The particulate fraction from a lymphoma cell line, LSTRA, was found to contain an apparent high level of tyrosine protein kinase activity. When this incubated with [gamma-32P]ATP in the presence 10 mM MnCl2, hydrolyzed, and assayed, 70--80% radioactivity recovered phosphoamino acids phosphotyrosine. Gel electrophoresis proteins showed that large portion 32P single molecular weight approximately 58,000. The phosphorylated residue identified as Detergent extracts LSTRA cells contained both Mr 58,000 enzyme responsible for its phosphorylation. These were catalyze phosphorylation synthetic peptide, Ile-Glu-Asp-Asn-Glu-Tyr-Thr-Ala-Arg-Gln-Gly, corresponding sequence around is pp60src; Km peptide reaction 5 mM. High-performance liquid chromatography used assay A second synthesized two additional arginine residues whose permitted be measured by simple using phosphocellulose paper. 3--4 mM, indicating did not alter affinity peptide.