Related Experiment Video
Updated: Aug 7, 2026

Dissecting Multi-protein Signaling Complexes by Bimolecular Complementation Affinity Purification (BiCAP)
Published on: June 15, 2018
Protocol for conditional mapping of proximal interactomes of dimeric protein complexes using a BioID-based
Abishankari Rajkumar1, Antoine Gaudreau-Lapierre1, Curtis L F Anthony1
1Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada; Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON K1H 8M5, Canada.
Abstract:
Here, we provide a protocol for conditional mapping of proximal interactomes of dimeric protein complexes using a BioID-based complementation approach. We describe steps for fusing amino- and carboxyl-terminal fragments of the biotin ligase TurboID to proteins known to interact within cells. This interaction drives re-formation of an active ligase and biotinylation of nearby proteins. We then detail procedures for capturing biotinylated proteins on a streptavidin affinity matrix for identification by mass spectrometry and Python-based scripts for identifying high-confidence proximal interactors. For complete details on the use and execution of this protocol, please refer to Rajkumar et al.1.
Related Concept Videos
Protein Networks
These interactions can be represented through maps depicting protein-protein interaction networks, represented as nodes and edges. Nodes are circles that are representative of a protein,...
Protein-protein Interfaces
Protein Complexes with Interchangeable Parts
The SCF ubiquitin ligase is a protein complex of five individual proteins. This complex attaches ubiquitin to other target proteins to mark them for degradation. In order to...

