Document Type
Article
Publication Version
Published Version
Publication Date
11-2003
Journal or Book Title
Journal of the American Chemical Society
Volume
125
Issue
51
First Page
15706
Last Page
15707
DOI
10.1021/ja0375380
Abstract
The Src homology 2 (SH2) domain of interleukin-2 tyrosine kinase (Itk) binds two separate ligands: a phosphotyrosine-containing peptide and the Itk Src homology 3 (SH3) domain. Binding specificity for these ligands is regulated via cis/trans isomerization of the Asn 286−Pro 287 imide bond in the Itk SH2 domain. In this study, we develop a novel method of analyzing chemical shift perturbation and cross-peak volumes to measure the affinities of both ligands for each SH2 conformer. We find that the cis imide bond containing SH2 conformer exhibits a 3.5-fold higher affinity for the Itk SH3 domain compared with binding of the trans conformer to the same ligand, while the trans conformer binds phosphopeptide with a 4-fold greater affinity than the cis-containing SH2 conformer. In addition to furthering the understanding of this system, the method presented here will be of general application in quantitatively determining the specificities of conformationally heterogeneous systems that use a molecular switch to regulate binding between multiple distinct ligands.
Rights
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Copyright Owner
American Chemical Society
Copyright Date
2003
Language
en
File Format
application/pdf
Recommended Citation
Breheny, Patrick J.; Laederach, Alain; Fulton, D. Bruce; and Andreotti, Amy H., "Ligand Specificity Modulated by Prolyl Imide Bond Cis/Trans Isomerization in the Itk SH2 Domain: A Quantitative NMR Study" (2003). Biochemistry, Biophysics and Molecular Biology Publications. 15.
https://lib.dr.iastate.edu/bbmb_ag_pubs/15
Comments
Reprinted (adapted) with permission from Journal of the American Chemical Society 125 (2003): 15706, doi:10.1021/ja0375380. Copyright 2003 American Chemical Society.