Spatial conformation and topography of the tyrosine aromatic ring in substrate recognition by protein tyrosine kinases.
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.
Institute of Biomolecular Chemistry of CNR, Padova Unit, via F. Marzolo 1, 35131 Padova, Italy. paolo.ruzza@unipd.it
Paolo
P
Ruzza
Luca
L
Cesaro
Dirk
D
Tourwé
Andrea
A
Calderan
Barbara
B
Biondi
Veronique
V
Maes
Ileana
I
Menegazzo
Alessio
A
Osler
Chiara
C
Rubini
Andrea
A
Guiotto
Lorenzo A
LA
Pinna
Gianfranco
G
Borin
Arianna
A
Donella-Deana
D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008968:Molecular Conformation; D018716:Molecular Mimicry; D009842:Oligopeptides / Q000138:chemical synthesis / Q000737:chemistry*; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000737:chemistry*; D013237:Stereoisomerism; D013329:Structure-Activity Relationship; D013379:Substrate Specificity; D014443:Tyrosine / Q000737:chemistry*
D009842:Oligopeptides; D014443:Tyrosine; D011505:Protein-Tyrosine Kinases