Interaction Proteomics facilitates the study of protein-protein interactions (PPIs). Dysregulation and inappropriate activation of protein complexes are associated with several diseases, including cancer. These interactions play a vital role in cellular processes and fundamental biological insights can be gained by studying networks of interacting proteins rather than individual proteins.
We use the Affinity Purification-Mass Spectrometry (AP-MS) platform to study protein interactions and complexes. AP-MS combines the specificity of antibody based protein purification with the sensitivity of mass spectrometry to identify and quantify putative interacting proteins. Either native antibody or an epitope-tagging approach may be used to purify protein complexes. In the epitope-tagging approach, a recombinant epitope-tagged bait protein of interest is expressed in cultured cells, and then the bait protein and associated proteins are then retrieved using an antibody against the epitope, followed by identification of prey proteins using mass-spectrometry. The mass-spectrometry data is analyzed and scoring metrics applied to identify those proteins that are specific to the bait of interest. AP-MS enables protein networks and complexes to be studied at the proteomic scale and it can be anticipated that the knowledge gained from such projects will fuel drug target discovery and prove indispensable to the emerging field of systems biology.
Janna Kiselar, Ph.D.
Case Center for Proteomics and Bioinformatics
Case Western Reserve University
10900 Euclid Avenue, BRB 947 Cleveland, Ohio 44106
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Saha, S., et al. Computational Framework for Analysis of Prey-Prey Associations in Interaction Proteomics Identifies Novel Human Protein-Protein Interactions and Networks., J. Proteome Res. 2012. doi: 10.1021/pr300227y
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