Photoaffinity Labeling
Photoaffinity Labeling — A technique where a photoreactive peptide probe is activated by UV light to form covalent bonds with its binding partner, identifying interaction sites.
What Is Photoaffinity Labeling?
Photoaffinity labeling uses a peptide probe containing a photo-reactive group (benzophenone, diazirine, or aryl azide) that forms a covalent bond to the target upon UV irradiation. The cross-linked complex is then analyzed by MS or SDS-PAGE to identify the target protein and map the binding site.
Workflow
- Probe: Peptide analog with photo-reactive amino acid (e.g., p-benzoyl-Phe) at a tolerated position
- Binding: Probe binds target under native conditions in the dark
- UV activation: 350-365 nm irradiation generates reactive carbene/nitrene that cross-links to nearest atoms
- ID: LC-MS/MS identifies cross-linked protein and exact contact residues
Frequently Asked Questions
What is Photoaffinity Labeling?
A technique where a photoreactive peptide probe is activated by UV light to form covalent bonds with its binding partner, identifying interaction sites.
Why is Photoaffinity Labeling important in peptide research?
Photoaffinity Labeling is a fundamental concept in analytical as it relates to peptide science. It directly influences experimental design, compound characterization, and the reliability of research outcomes across biochemistry and molecular biology disciplines.
Authority Sources
- Photoaffinity Labeling on Wikipedia
- Search Photoaffinity Labeling on PubChem (NIH)
- Research articles on ScienceDirect