Abstract
We utilized a novel peptide library approach to identify specific inhibitors of ZAP-70, a protein Tyr kinase involved in T cell activation. By screening more than 6 billion peptides oriented by a common Tyr residue for their ability to bind to ZAP-70, we determined a consensus optimal peptide. A Phe-for-Tyr substituted version of the peptide inhibited ZAP-70 protein Tyr kinase activity by competing with protein substrates (K(I) of 2 microM). The related protein Tyr kinases, Lck and Syk, were not significantly inhibited by the peptide. When introduced into intact T cells, the peptide blocked signaling downstream of ZAP-70, including ZAP-70-dependent gene induction, without affecting upstream Tyr phosphorylation. Thus, screening Tyr-oriented peptide libraries can identify selective peptide inhibitors of protein Tyr kinases.
Publication types
-
Research Support, U.S. Gov't, P.H.S.
MeSH terms
-
Amino Acid Sequence
-
Enzyme Inhibitors / chemical synthesis
-
Enzyme Inhibitors / chemistry*
-
Enzyme Inhibitors / pharmacology*
-
Genes, Reporter
-
Humans
-
Interleukin-2 / genetics
-
Isoenzymes / metabolism
-
Jurkat Cells
-
Kinetics
-
Lymphocyte Activation
-
Molecular Sequence Data
-
Peptide Library*
-
Peptides / chemical synthesis
-
Peptides / chemistry*
-
Peptides / pharmacology
-
Phospholipase C gamma
-
Protein-Tyrosine Kinases / antagonists & inhibitors*
-
T-Lymphocytes / enzymology
-
T-Lymphocytes / immunology
-
Transfection
-
Type C Phospholipases / metabolism
-
ZAP-70 Protein-Tyrosine Kinase
Substances
-
Enzyme Inhibitors
-
Interleukin-2
-
Isoenzymes
-
Peptide Library
-
Peptides
-
Protein-Tyrosine Kinases
-
ZAP-70 Protein-Tyrosine Kinase
-
ZAP70 protein, human
-
Type C Phospholipases
-
Phospholipase C gamma