Ruzza Paolo, Cesaro Luca, Tourwé Dirk, Calderan Andrea, Biondi Barbara, Maes Veronique, Menegazzo Ileana, Osler Alessio, Rubini Chiara, Guiotto Andrea, Pinna Lorenzo A, Borin Gianfranco, Donella-Deana Arianna
Institute of Biomolecular Chemistry of CNR, Padova Unit, via F. Marzolo 1, 35131 Padova, Italy.
J Med Chem. 2006 Mar 23;49(6):1916-24. doi: 10.1021/jm051080q.
The side chain orientation of the tyrosine residue included in a peptide, which is an excellent substrate of Syk tyrosine kinase, was fixed in different conformations by either incorporating the tyrosine in cyclic structures (6-OH-Tic, 5-OH-Aic, and Hat derivatives) or adding a sterically bulky substituent in the tyrosine side chain moiety (beta-MeTyr). Synthetic peptides containing tyrosine analogues displaying different side chain orientations were analyzed by NMR techniques and tested as potential substrates of the nonreceptor tyrosine kinases Syk, Csk, Lyn, and Fyn. The "rotamer scan" of the phosphorylatable residue generated optimal substrates in terms of both phosphorylation efficiency and selectivity for Syk tyrosine kinase, while the peptidomimetics were not recognized by the other tyrosine kinases. In particular, l-beta-MeTyr and d-Hat containing peptides resulted to be both suitable substrates for the specific monitoring of Syk and consensus sequence scaffolds for the design of potential inhibitors highly selective for this tyrosine kinase.
