title: Small peptides containing phosphotyrosine and adjacent alphaMe-phosphotyrosine or its mimetics as highly potent inhibitors of Grb2 SH2 domain.
abstract: A series of small peptides with the sequence mAZ-pTyr-Xaa-Asn-NH(2), where Xaa denotes alpha-methylphosphotyrosine or its carboxylic mimetics, were synthesized as inhibitors of the Grb2 SH2 domain. Peptide 3 with (alpha-Me)pTyr as Xaa has the highest affinity for Grb2 (K(d) = 3 +/- 1 nM) and exhibits to date the best inhibitory activity (IC(50) = 11 +/- 1 nM) to displace PSpYVNVQN-Grb2 interaction in an ELISA test. The lower affinities of peptides with (alpha-Me)Tyr, (alpha-Me)Phe(4-CO(2)H), or (alpha-Me)Phe(4-CH(2)CO(2)H) as Xaa demonstrate the importance of a double charged phosphate group at the pY+1 position. Molecular modeling showed additional hydrogen bond interactions provided by the (alpha-Me)pTyr residue with the Grb2 SH2 domain. These results thus show that the effect of hydrophobic pY+1 residues, initially put forth to increased the binding affinities, can be further enhanced by a (-Me)pTyr residue which has both hydrophobic and hydrophilic properties.
authors.affiliation: Département de Pharmacochimie Moléculaire et Structurale, INSERM U266-CNRS UMR 8600, UFR des Sciences Pharmaceutiques et Biologiques, 4, avenue de l'Observatoire, 75270 Paris Cedex 06, France.
authors.forename: W Q
authors.initials: WQ
authors.lastname: Liu
authors.forename: M
authors.initials: M
authors.lastname: Vidal
authors.forename: N
authors.initials: N
authors.lastname: Gresh
authors.forename: B P
authors.initials: BP
authors.lastname: Roques
authors.forename: C
authors.initials: C
authors.lastname: Garbay
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D001665:Binding Sites; D051380:GRB2 Adaptor Protein; D008958:Models, Molecular; D010455:Peptides / Q000737:chemistry* / Q000494:pharmacology; D019000:Phosphotyrosine / Q000737:chemistry*; D011485:Protein Binding; D011506:Proteins / Q000037:antagonists & inhibitors*; D018909:src Homology Domains
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D051380:GRB2 Adaptor Protein; D010455:Peptides; D011506:Proteins; D019000:Phosphotyrosine