Download MendeleyThe Magic of Linking Rings: Discovery of a Unique Photoinduced Fluorescent Protein Crosslink.
Lu, M., Toptygin, D., Xiang, Y., Shi, Y., Schwieters, C.D., Lipinski, E.C., Ahn, J., Byeon, I.L., Gronenborn, A.M.(2022) J Am Chem Soc 144: 10809-10816
- PubMed: 35574633
- DOI: https://doi.org/10.1021/jacs.2c02054
- Primary Citation of Related Structures:
7TA8 - PubMed Abstract:
Fluorosubstituted tryptophans serve as valuable probes for fluorescence and nuclear magnetic resonance (NMR) studies of proteins. Here, we describe an unusual photoreactivity introduced by replacing the single tryptophan in cyclophilin A with 7-fluoro-tryptophan. UV exposure at 282 nm defluorinates 7-fluoro-tryptophan and crosslinks it to a nearby phenylalanine, generating a bright fluorophore. The crosslink-containing fluorescent protein possesses a large quantum yield of ∼0.40 with a fluorescence lifetime of 2.38 ns. The chemical nature of the crosslink and the three-dimensional protein structure were determined by mass spectrometry and NMR spectroscopy. To the best of our knowledge, this is the first report of a Phe-Trp crosslink in a protein. Our finding may break new ground for developing novel fluorescence probes and for devising new strategies to exploit aromatic crosslinks in proteins.
Organizational Affiliation:
Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261, United States.
