SWTY--a general peptide probe for homogeneous solution binding assay of 14-3-3 proteins

Anal Biochem. 2006 Feb 15;349(2):186-96. doi: 10.1016/j.ab.2005.11.030. Epub 2005 Dec 15.

Abstract

Dimeric 14-3-3 proteins exert diverse functions in eukaryotes by binding to specific phosphorylated sites on diverse target proteins. Critical to the physiological function of 14-3-3 proteins is the wide range of binding affinity to different ligands. The existing information of binding affinity is mainly derived from nonhomogeneous-based methods such as surface plasmon resonance and quantitative affinity precipitation. We have developed a fluorescence anisotropy peptide probe using a genetically isolated 14-3-3-binding SWTY motif. The synthetic 5-(and-6)-carboxyfluorescein(FAM)-RGRSWpTY-COOH peptide, when bound to 14-3-3 proteins, exhibits a seven-fold increase in fluorescence anisotropy. Different from the existing assays for 14-3-3 binding, this homogeneous assay tests the interaction directly in solution. Hence it permits more accurate determination of the dissociation constants of 14-3-3 binding molecules. Protocols for a simple mix-and-read format have been developed to evaluate 14-3-3 protein interactions using either purified recombinant 14-3-3 fusion proteins or native 14-3-3s in crude cell lysate. Optimal assay conditions for high-throughput screening for modulators of 14-3-3 binding have been determined.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • 14-3-3 Proteins / metabolism*
  • Amino Acid Sequence
  • Cell Line
  • Humans
  • Hydrogen-Ion Concentration
  • Molecular Probes*
  • Oligopeptides / metabolism*
  • Protein Binding
  • Sensitivity and Specificity
  • Solutions

Substances

  • 14-3-3 Proteins
  • Molecular Probes
  • Oligopeptides
  • Solutions