A bioinspired redox relay that mimics radical interactions of the Tyr-His pairs of photosystem II.

Autor: Megiatto JD Jr; 1] Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287-1604, USA [2]., Méndez-Hernández DD; Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287-1604, USA., Tejeda-Ferrari ME; Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287-1604, USA., Teillout AL; 1] Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287-1604, USA [2] Laboratoire de Chimie Physique, Groupe d'Electrochimie et de Photoélectrochimie, UMR 8000, CNRS, Université Paris-Sud, Batiment 350, 91405 Orsay Cedex, France., Llansola-Portolés MJ; Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287-1604, USA., Kodis G; Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287-1604, USA., Poluektov OG; NanoBio Interface Group, Center for Nanoscale Materials and Chemical Sciences and Engineering Division, Argonne National Laboratory Argonne, Illinois 60439, USA., Rajh T; NanoBio Interface Group, Center for Nanoscale Materials and Chemical Sciences and Engineering Division, Argonne National Laboratory Argonne, Illinois 60439, USA., Mujica V; Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287-1604, USA., Groy TL; Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287-1604, USA., Gust D; Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287-1604, USA., Moore TA; Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287-1604, USA., Moore AL; Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287-1604, USA.
Jazyk: angličtina
Zdroj: Nature chemistry [Nat Chem] 2014 May; Vol. 6 (5), pp. 423-8. Date of Electronic Publication: 2014 Feb 09.
DOI: 10.1038/nchem.1862
Abstrakt: In water-oxidizing photosynthetic organisms, light absorption generates a powerfully oxidizing chlorophyll complex (P680(•+)) in the photosystem II reaction centre. This is reduced via an electron transfer pathway from the manganese-containing water-oxidizing catalyst, which includes an electron transfer relay comprising a tyrosine (Tyr)-histidine (His) pair that features a hydrogen bond between a phenol group and an imidazole group. By rapidly reducing P680(•+), the relay is thought to mitigate recombination reactions, thereby ensuring a high quantum yield of water oxidation. Here, we show that an artificial reaction centre that features a benzimidazole-phenol model of the Tyr-His pair mimics both the short-internal hydrogen bond in photosystem II and, using electron paramagnetic resonance spectroscopy, the thermal relaxation that accompanies proton-coupled electron transfer. Although this artificial system is much less complex than the natural one, theory suggests that it captures the essential features that are important in the function of the relay.
Databáze: MEDLINE