Profiling substrate specificities of protein tyrosine phosphatases: Toward the development of highly selective inhibitors

BIOL 257

Sayantan Mitra, smitra@usc.edu, Department of Chemistry, University of Southern California, 810 Downey Way, Los Angeles, CA 90089 and Amy M. Barrios, Deparment of Medicinal Chemistry, University of Southern California, 30 South 2000 East, Salt Lake City, UT 84112.
Protein tyrosine phosphatases (PTPs) constitute an important class of enzymes that are involved in numerous cellular processes. Although PTPs are attractive therapeutic targets, not much is known about the biological roles of most PTPs, and selective inhibition of these highly homologous enzymes has proven difficult so far. Here we report the high-yielding synthesis of an enantiomerically pure phosphocoumarin-based amino acid (pCAP) and its incorporation into peptides via standard solid-phase synthesis. The resultant substrates are efficiently hydrolyzed by both bacterial and human PTPs and exhibit a large increase in fluorescence upon hydrolysis demonstrating that the pCAP residue can be easily incorporated into peptides. The pCAP moiety was further used to synthesize positionally scanned combinatorial libraries of peptide substrates in order to profile the substrate preferences of a number of PTPs. The specificity profiles obtained in this study have been utilized in the design of potent, selective PTP inhibitors.
 

Enzymes
4:30 PM-6:30 PM, Wednesday, 13 September 2006 Moscone Center -- Hall D, Poster

Sci-Mix
8:00 PM-10:00 PM, Monday, 11 September 2006 Moscone Center -- Hall D, Sci-Mix

Division of Biological Chemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006