Interrogating Proteolytic Pathways
Play: http://videocast.nih.gov/launch.asp?14288
 
Air date: Friday, February 08, 2008, 10:00:00 AM
Category: Proteomics
Description: This presentation will describe the mission and the activities of the Center on Proteolytic Pathways (CPP), a technology development effort sponsored by the NIH Roadmap Initiative. The main purpose of the CPP is to develop technological advances relevant to the interrogation of proteases and proteolytic pathways. A three-pronged strategy is being applied to attain the ?holy grail? of proteolysis; to identify all active proteases, their substrates, and end products, that are present in a biological sample. Activity-based proteomics, which makes use of chemical probes to tag enzyme active sites, is being modified to mass tag broad families of proteases. These activity-based probes facilitate the identification and quantification of proteases in crude biological sample. In many cases the same probes even allow one to image protease activity in cells and whole animals. A complementary approach, Product Terminal Isotope Coding (PROTIC), is being developed to identify the products of proteolysis. PROTIC selectively tags the N-termini present in a biological sample. Since any protein that has been cleaved by a protease displays an additional N-terminus, the products of proteolysis are readily apparent. Finally, to match the identified proteases with the appropriate end products, we extrapolate from a database of protease substrate specificity. This database is being constructed with Substrate Phage Profiling. This method makes use of substrate phage display, in which a highly diverse peptide library is exposed to a protease. The substrate recognition specificity of a protease is derived from sequences of the cleaved peptides. Information on the peptide recognition specificity is combined with filters to exclude potential cut sites that are buried in the interior of the protein, or that are not expressed in the same tissue or sub-cellular location as the protease, to predict the putative physiologic and pathophysiologic substrates. Altogether we intend to put forward a platform that will transform research on proteolysis by providing innumerable biological hypotheses that can be tested in research laboratories.

http://proteome.nih.gov
Author: Jeffrey Smith, Burnham Institute
Runtime: 66 minutes
Rights: This is a work of the United States Government.
CIT File ID: 14288
CIT Live ID: 6278
Permanent link: http://videocast.nih.gov/launch.asp?14288
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