NAPA-ID: a proximity-based system to decode protein-protein interactions
This technology is a compact, robust photonic crystal-based spectrometer that extracts wavelength-specific information from light without moving parts, enabling miniaturized, robust IR spectral analysis.
Decoding protein interaction networks without cellular engineering
Protein-protein interactions are central to normal cellular function, and disruptions in these interactions underlie many diseases, including cancer, infectious diseases, and neurological disorders. Existing methods for mapping protein interactomes frequently require genetic modification of cells to express tagged or enzyme-fused versions of the protein of interest. These requirements limit applicability in primary cells, non-dividing or terminally differentiated cells, and clinically relevant samples. There is a need for an interaction-mapping approach that does not rely on engineered expression systems while remaining compatible with established biochemical readouts.
The Technology: Antibody-guided enzymatic proximity labeling using nanobody-APEX2
This technology, termed NANobody-guided Proximity with APEX (NAPA-ID), enables proximity-dependent labeling of proteins surrounding a target protein without genetic manipulation of the cell. The method uses an engineered APEX2–nanobody fusion that recognizes common primary antibody species (rabbit, mouse, goat, and rat), allowing APEX2 to be targeted to a protein of interest via standard immunostaining. Cells are fixed and permeabilized, labeled with a primary antibody, and incubated with the nanobody–APEX2 reagent. Upon addition of biotin and hydrogen peroxide, APEX2 biotinylates nearby proteins, which are subsequently enriched by streptavidin pull-down and identified by mass spectrometry or western blotting. By leveraging antibody-based targeting, NAPA-ID is broadly applicable across proteins and cell types and integrates seamlessly with established biochemical workflows.
The technology has been demonstrated in vitro using fixed and permeabilized cells.
Applications:
- Decoding protein-protein interactions for diverse target proteins
- Mapping protein-RNA interactions through proximity labeling strategies
- Drug target identification and mechanism-of-action studies
- Biomarker discovery
- Characterization of protein complexes
- Evaluation of disease-associated or pathogenic mutations on protein complex formation
- Functional analysis of proteins in health and disease
- Research use in primary, non-dividing, or difficult-to-engineer cell types
Advantages:
- Does not require genetic engineering of cells
- Leverages existing antibody reagents for target flexibility
- Compatible with diverse cell types, including primary and terminally differentiated cells
- Integrates with established streptavidin pull-down and proteomics workflows
- Enables rapid target-specific interactome analysis
- Reduces barriers associated with plasmid or vector construction
Lead Inventor:
Related Publications:
Tech Ventures Reference:
- Licensing Contact: Jerry Kokoshka