A computational perspective on the photochemistry of photosensory proteins: phytochromes and Anabaena sensory rhodopsin
2012 (English)In: Quantum Simulations of Materials and Biological Systems / [ed] Jun Zeng, Rui-Qin Zhang and Herbert R. Treutlein, Springer Netherlands, 2012, 169-194 p.Chapter in book (Refereed)
The merits of quantum simulations in photobiology are illustrated by presenting recent computational studies investigating the basic photochemistry of phytochromes, a ubiquitous family of photosensory proteins, and Anabaena sensory rhodopsin, a recently discovered member of the rhodopsins. Focusing on the chromophore photoisomerization reactions that trigger these proteins’ responses to light and using density functional methods and multiconfigurational ab initio methods in combination with molecular mechanics, three surprising results can be singled out. First, it is found that the photochemical reactivity of the bilin chromophores of phytochromes is fundamentally different in solution and in the protein, with different photoisomerization channels being preferred. Second, it is found that the two retinal photoisomerizations that govern the interconversion of Anabaena sensory rhodopsin between its two major forms proceed in such a way that the chromophore completes a full 360° rotation during one photocycle. This means that this protein is a biological realization of a light-driven molecular rotor. Third, and finally, it is demonstrated that the stereochemical origin of this remarkable behavior is actually a key element for the function of a class of synthetic light-driven molecular rotors developed from overcrowded alkenes, thereby identifying Anabaena sensory rhodopsin as a possible source of inspiration for the future design and construction of such molecular machines.
Place, publisher, year, edition, pages
Springer Netherlands, 2012. 169-194 p.
IdentifiersURN: urn:nbn:se:liu:diva-89824DOI: 10.1007/978-94-007-4948-1_10ISBN: 978-94-007-4947-4ISBN: e-978-94-007-4948-1OAI: oai:DiVA.org:liu-89824DiVA: diva2:609851