Photoaffinity labeling explained

Photoaffinity labeling is a chemoproteomics technique used to attach "labels" to the active site of a large molecule, especially a protein. The "label" attaches to the molecule loosely and reversibly, and has an inactive site which can be converted using photolysis into a highly reactive form, which causes the label to bind more permanently to the large molecule via a covalent bond.^{[1] [2]} The technique was first described in the 1970s.^[3] Molecules that have been used as labels in this process are often analogs of complex molecules, in which certain functional groups are replaced with a photoreactive group, such as an azide, a diazirine or a benzophenone.^{[4] [5] [6]}

Notes and References

1. http://www.merriam-webster.com/medical/photoaffinity%20labeling Photoaffinity labeling
2. http://goldbook.iupac.org/P04578.html Photoaffinity labeling
3. 10.1073/pnas.70.9.2567 . Ruoho . A. E. . Kiefer . H. . Roeder . P. E. . Singer . S. J. . The mechanism of photoaffinity labeling . Proceedings of the National Academy of Sciences of the United States of America . 70 . 9 . 2567–2571 . 1973 . 4517671 . 427057. 1973PNAS...70.2567R . free .
4. Bush . J. T. . Walport . L. J. . McGouran . J. F. . Leung . I. K. H. . Berridge . G. . The Ugi four-component reaction enables expedient synthesis and comparison of photoaffinity probes . 10.1039/C3SC51708J. Chemical Science. 4. 12. 4115–4120 . 2013 . free.
5. Panov . M. S. . Voskresenska . V. D. . Ryazantsev . M. N. . Tarnovsky . A. N. . Wilson . R. M. . 5-Azido-2-aminopyridine, a New Nitrene/Nitrenium Ion Photoaffinity Labeling Agent That Exhibits Reversible Intersystem Crossing between Singlet and Triplet Nitrenes . 10.1021/ja405637b . Journal of the American Chemical Society . 135 . 51 . 19167–19179 . 2013 . 24219134 .
6. Akiyama . S. . Cornwell . M. M. . Kuwano . M. . Pastan . I. . Gottesman . M. M. . Most drugs that reverse multidrug resistance also inhibit photoaffinity labeling of P-glycoprotein by a vinblastine analog . Molecular Pharmacology . 33 . 2 . 144–147 . 1988 . 2893251.