14-3-3 inhibitor

The peptide sequence, PHCVPRDLSWLDLEANMCLP, named R18, was identified as an unphosphorylated peptide that binds to 14-3-3 proteins with high affinity (Kd=80 nM). It has been shown to bind to the same amphipathic groove on the surface of 14-3-3 as phosphorylated peptides. R18 can inhibit the formation of the 14-3-3-Raf-1 complex, reduce Raf-1 dependent transcriptional activity in cells and block the activation of ExoS by 14-3-3. It binds to all the 14-3-3 isoforms with equal affinities. This peptide is useful for competitive inhibition experiments and the N-terminal biotin allows it to be used in assay with streptavidin bound membranes.