@article{Chukhutsina:2022:10.1038/s41467-022-34137-4,
author = {Chukhutsina, VU and Baxter, JM and Fadini, A and Morgan, RM and Pope, MA and Maghlaoui, K and Orr, CM and Wagner, A and van, Thor JJ},
doi = {10.1038/s41467-022-34137-4},
journal = {Nat Commun},
title = {Light activation of Orange Carotenoid Protein reveals bicycle-pedal single-bond isomerization.},
url = {http://dx.doi.org/10.1038/s41467-022-34137-4},
volume = {13},
year = {2022}
}

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TY  - JOUR
AB  - Orange Carotenoid protein (OCP) is the only known photoreceptor which uses carotenoid for its activation. It is found exclusively in cyanobacteria, where it functions to control light-harvesting of the photosynthetic machinery. However, the photochemical reactions and structural dynamics of this unique photosensing process are not yet resolved. We present time-resolved crystal structures at second-to-minute delays under bright illumination, capturing the early photoproduct and structures of the subsequent reaction intermediates. The first stable photoproduct shows concerted isomerization of C9'-C8' and C7'-C6' single bonds in the bicycle-pedal (s-BP) manner and structural changes in the N-terminal domain with minute timescale kinetics. These are followed by a thermally-driven recovery of the s-BP isomer to the dark state carotenoid configuration. Structural changes propagate to the C-terminal domain, resulting, at later time, in the H-bond rupture of the carotenoid keto group with protein residues. Solution FTIR and UV/Vis spectroscopy support the single bond isomerization of the carotenoid in the s-BP manner and subsequent thermal structural reactions as the basis of OCP photoreception.
AU  - Chukhutsina,VU
AU  - Baxter,JM
AU  - Fadini,A
AU  - Morgan,RM
AU  - Pope,MA
AU  - Maghlaoui,K
AU  - Orr,CM
AU  - Wagner,A
AU  - van,Thor JJ
DO  - 10.1038/s41467-022-34137-4
PY  - 2022///
TI  - Light activation of Orange Carotenoid Protein reveals bicycle-pedal single-bond isomerization.
T2  - Nat Commun
UR  - http://dx.doi.org/10.1038/s41467-022-34137-4
UR  - https://www.ncbi.nlm.nih.gov/pubmed/36307413
VL  - 13
ER  - 

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