Kinetics of p56lck and p60src Src homology 2 domain binding to tyrosine-phosphorylated peptides determined by a competition assay or surface plasmon resonance.
AUTOR(ES)
Payne, G
RESUMO
Src homology 2 (SH2) domains are phosphotyrosine-binding modules found within various signal-transducing proteins. We have determined by 125I competition assay and surface plasmon resonance that the SH2 domains of Src and Lck bind to a variety of phosphopeptides with similar affinity and specificity. Both bound with highest affinity [Kd(app) approximately 3.7 nM; ka = 2.4 x 10(5) M-1 x s-1; kd = 1.2 x 10(-3) s-1] a phosphopeptide having a Tyr(P)-Glu-Glu-Ile motif found in the hamster polyomavirus middle-sized tumor antigen. Intermediate affinity (5- to 40-fold lower) was observed with phosphopeptides corresponding to the regulatory domains of Src and Lck, containing Tyr527 and Tyr505, respectively. Lowest affinity (80- to 300-fold lower) was observed with phosphopeptides corresponding to phosphorylated tyrosines of GTPase-activating protein, insulin receptor substrate 1, and SH2 domain-containing protein-tyrosine-phosphatase 1.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=46621Documentos Relacionados
- The Src homology 2 domain of the protein-tyrosine kinase p56lck mediates both intermolecular and intramolecular interactions.
- Analysis of the binding of the Src homology 2 domain of Csk to tyrosine-phosphorylated proteins in the suppression and mitotic activation of c-Src.
- Stable association of activated pp60src with two tyrosine-phosphorylated cellular proteins.
- Modification of Ser59 in the unique N-terminal region of tyrosine kinase p56lck regulates specificity of its Src homology 2 domain.
- The noncatalytic src homology region 2 segment of abl tyrosine kinase binds to tyrosine-phosphorylated cellular proteins with high affinity.