Toward a comprehensive view of the molecular bases of magnetoreception from realistic biological models - Aurélien de la Lande

The molecular basis of magnetoreception continues to stimulate active research worldwide. The dominant models attribute the magnetic sense to coherent spin dynamics in radical pairs/triads within the flavo-protein cryptochrome. Our research groups have embarked on an ambitious theoretical program aiming at unravelling the molecular basis of magnetoreception, combining spin dynamics, accurate electronic structure calculations and molecular dynamics simulations of proteins.
In the first part of this seminar, we will summarize our results on radical pair production in cryptochrome proteins by cascades of photoinduced electron transfers. We will contrast various mechanisms leading to the formation of flavin and tryptophan radicals[1,2]. We will evidence the influence of nuclear quantum effects or other fine quantum effects.
In the second part we will lay the foundations of the assessment of an original triad of radical model. We will first illustrate the advantages of a triad radical mechanism within an actual avian cryptochrome protein[3]. We will report accurate hyperfine coupling tensors obtained by auxiliary density functional theory along classical molecular dynamics simulations[4]. Finally, we will report recent exciting findings about putative superoxide anions location sites that could, in the context of the triad model, both enhance the sensitivity of the compass and protect the protein against oxidative stress. Perspectives for future studies will be proposed.
References [1] Cailliez F, Muller P, Firmino T, Pernot P and de la Lande A 2016 Energetics of Photoinduced Charge Migration within the Tryptophan Tetrad of an Animal (6-4) Photolyase J. Am. Chem. Soc. 138 1904-15 [2] Firmino T, Mangaud E, Cailliez F, Devolder A, Mendive-Tapia D, Gatti F, Meier C, Desouter-Lecomte M and de la Lande A 2016 Quantum effects in ultrafast electron transfers within cryptochromes Phys. Chem. Chem. Phys. 18 21442-57 [3] Deviers J, Cailliez F, de la Lande A and Kattnig D R 2022 Anisotropic magnetic field effects in the re-oxidation of cryptochrome in the presence of scavenger radicals J. Chem. Phys. 156 025101 [4] Deviers J, Cailliez F, Gutierrez B Z, Kattnig D R and de la Lande A 2022 Ab initio derivation of flavin hyperfine interactions for the protein magnetosensor cryptochrome Phys. Chem. Chem. Phys. 24 16784-98.