An optimized co-immunoprecipitation protocol for the analysis of endogenous protein-protein interactions in cell lines using mass spectrometry

This protocol represents an optimized proteomics-based protocol for the endogenous protein enrichment and protein-protein interaction analysis. This 2-step protocol consists of: 1) co-immunoprecipitation of the bait protein; 2) the bait-protein interactions analysis using LC-MS/MS. Here, we used Dynabeads® for the enrichment of the target protein (the bait) and its interactors. We have tested the protocol using several different cell lines. Our conclusion is that the protocol is applicable to different cell lines and species. For complete details on the use and execution of this protocol, please refer to Lagundžin et al. (2019). Keywords: Mass Spectrometry; Protein Biochemistry; Protein expression and purification; Proteomics.