Mapping the subsite preferences of protein tyrosine phosphatase PTP-1B using combinatorial chemistry approaches.
Biochemistry
; 37(45): 15598-606, 1998 Nov 10.
Article
em En
| MEDLINE
| ID: mdl-9843364
ABSTRACT
Protein tyrosine phosphatases (PTPases) are important regulators of signal transduction systems, but the specificity of their action is largely unexplored. We have approached this problem by attempting to map the subsite preferences of these enzymes using combinatorial chemistry approaches. Protein-tyrosine peptidomimetics containing nonhydrolyzable phosphotyrosine analogues bind to PTPases with high affinity and act as competitive inhibitors of phosphatase activity. Human PTP-1B, a PTPase implicated to play an important role in the regulation of growth factor signal transduction pathways, was used to screen a synthetic combinatorial library containing malonyltyrosine as a phosphotyrosine mimic. Using two cross-validating combinatorial chemistry screening approaches, one using an iterative method and the other employing library affinity selection-mass spectrometric detection, peptides with high affinity for PTP-1B were identified and subsite preferences were detailed by quantitatively comparing residues of different character. Consistent with previous observations, acidic residues were preferred in subsites X-3 and X-2. In contrast, aromatic substitutions were clearly preferred at the X-1 subsite. This information supports the concept that this class of enzymes may have high substrate specificity as dictated by the sequence proximal to the phosphorylation site. The results are discussed with regards to the use of combinatorial techniques in order to elucidate the interplay between enzyme subsites.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fosfopeptídeos
/
Mapeamento de Peptídeos
/
Desenho de Fármacos
/
Proteínas Tirosina Fosfatases
/
Biblioteca de Peptídeos
/
Inibidores Enzimáticos
Tipo de estudo:
Prognostic_studies
Limite:
Humans
Idioma:
En
Revista:
Biochemistry
Ano de publicação:
1998
Tipo de documento:
Article
País de afiliação:
Estados Unidos