7ta8

Publication Abstract from PubMed

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 approximately 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.

The Magic of Linking Rings: Discovery of a Unique Photoinduced Fluorescent Protein Crosslink.,Lu M, Toptygin D, Xiang Y, Shi Y, Schwieters CD, Lipinski EC, Ahn J, Byeon IL, Gronenborn AM J Am Chem Soc. 2022 Jun 22;144(24):10809-10816. doi: 10.1021/jacs.2c02054. Epub , 2022 May 14. PMID:35574633^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.