Dimeric peptidic probes as tools for the study of tandem PDZ domain-containing proteins

ORGN 132

Matthieu Sainlos, sainlos@mit.edu, Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, Christel Poujol, Plateforme d'Imagerie Cellulaire de l'Institut de Neurosciences, Institut François Magendie, 146 rue Leo Saignat, Bordeaux, 33077, France, Daniel Choquet, dchoquet@u-bordeaux2.fr, UMR 5091 CNRS-Université de bordeaux, Institut François Magendie, 146 rue Leo Saignat, Bordeaux, 33077, France, and Barbara Imperiali, imper@mit.edu, Department of Chemistry and Department of Biology, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA 02139.
Closely linked PDZ domains, either as tandem within the same protein or as oligomers, are a common feature of scaffolding proteins and appear to be important for regulation of clustering and localization of multiprotein complexes. In order to characterize the role of multivalency in this form of protein/protein interaction, we have designed a series of monomeric and dimeric probes. We report here a versatile approach for obtaining dimeric peptidic ligands by SPPS, which relies on “click” chemistry for the ligation of the two units. Incorporation of solvatochromic fluorophores enables the quantitative evaluation of their binding properties to tandem domains. The study was extended to a cellular context by developing a FRET/FLIM assay in COS cells with fluorescent fusion proteins and cell permeant probes. The results indicate that multivalent ligands have a significantly enhanced affinity for tandem PDZ domains and can efficiently disrupt interactions between tandem-containing proteins and their binding partners.
 

Total Synthesis, Materials, Devices and Switches, Molecular Recognition and Self-Assembly, Biologically-Related Molecules and Processes
8:00 PM-10:00 PM, Sunday, August 19, 2007 BCEC -- Exhibit Hall - B2, Poster

Division of Organic Chemistry

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007