Open AccessKinetics of p56lck and p60src Src homology 2 domain binding to tyrosine-phosphorylated peptides determined by a competition assay or surface plasmon resonance.
Author(s) -
Gillian Payne,
Steven E. Shoelson,
Gerald Gish,
Tony Pawson,
Christopher T. Walsh
Publication year - 1993
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.90.11.4902
Subject(s) - sh2 domain , proto oncogene tyrosine protein kinase src , surface plasmon resonance , phosphopeptide , tyrosine , phosphorylation , protein tyrosine phosphatase , chemistry , irs1 , biochemistry , sh3 domain , phosphatase , receptor–ligand kinetics , biophysics , biology , receptor , insulin receptor , materials science , insulin resistance , endocrinology , nanoparticle , insulin , nanotechnology
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.