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Tracking the Electron Transfer Cascade in European Robin Cryptochrome 4 Mutants

Timmer, Daniel; Frederiksen, Anders; Luenemann, Daniel C. C.; Thomas, Anitta R.; Xu, Jingjing; Bartölke, Rabea; Schmidt, Jessica; Kubař, Tomáš 1; De Sio, Antonietta; Solov’yov, Ilia A.; Mouritsen, Henrik; Lienau, Christoph
1 Institut für Physikalische Chemie (IPC), Karlsruher Institut für Technologie (KIT)

Abstract:

The primary step in the mechanism by which migratory birds sense the Earth’s magnetic field is thought to be the light-induced formation of long-lived magnetically sensitive radical pairs within cryptochrome flavoproteins located in the birds’ retinas. Blue-light absorption by the non-covalently bound flavin chromophore triggers sequential electron transfers along a chain of four tryptophan residues toward the photoexcited flavin. The recently demonstrated ability to express cryptochrome 4a from the night-migratory European robin (Erithacus rubecula), ErCry4a, and to replace each of the tryptophan residues by a redox-inactive phenylalanine offers the prospect of exploring the roles of the four tryptophans. Here, we use ultrafast transient absorption spectroscopy to compare wild type ErCry4a and four mutants having a phenylalanine at different positions in the chain. We find that each of the three tryptophan residues closest to the flavin adds a distinct relaxation component (time constants: 0.5, 30, and 150 ps) in the transient absorption data. The dynamics of the mutant containing a phenylalanine at the fourth position, furthest from the flavin, are very similar to those of wild type ErCry4a, except for a reduced concentration of long-lived radical pairs. ... mehr


Verlagsausgabe §
DOI: 10.5445/IR/1000160074
Veröffentlicht am 03.07.2023
Originalveröffentlichung
DOI: 10.1021/jacs.3c00442
Scopus
Zitationen: 10
Dimensions
Zitationen: 13
Cover der Publikation
Zugehörige Institution(en) am KIT Institut für Physikalische Chemie (IPC)
Publikationstyp Zeitschriftenaufsatz
Publikationsdatum 31.05.2023
Sprache Englisch
Identifikator ISSN: 0002-7863, 1520-5126, 1943-2984
KITopen-ID: 1000160074
Erschienen in Journal of the American Chemical Society
Verlag American Chemical Society (ACS)
Band 145
Heft 21
Seiten 11566–11578
Vorab online veröffentlicht am 17.05.2023
Nachgewiesen in Dimensions
Web of Science
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