Triggered functional dynamics of AsLOV2 by time-resolved electron paramagnetic resonance at high magnetic fields
Abstract
We present time-resolved Gd-Gd electron paramagnetic resonance (TiGGER) at 240 GHz for tracking inter-residue distances during a protein's mechanical cycle in solution state. TiGGER makes use of Gd-sTPATCN as spin labels, whose favorable qualities include a spin-7 / 2 EPR-active center, a short linker, a narrow intrinsic linewidth, and virtually no anisotropy at high magnetic fields (8.6 T) when compared to nitroxide spin labels. Using TiGGER, we are able to determine that upon light activation, the J α -helix and N-terminus of AsLOV2 separate in less than 1 s and relax back to equilibrium with a time constant of approximately 60 s. TiGGER reveals that the light-activated longrange mechanical motion is slowed in the Q513A variant of AsLOV2 and is correlated to the similarly slowed relaxation of the optically excited chromophore as described in recent literature. Our results demonstrate that TiGGER has the potential to valuably complement existing methods for the study of triggered functional dynamics in proteins.
Citation
Maity , S , Price , B D , Wilson , C B , Mukherjee , A , Starck , M , Parker , D , Wilson , M Z , Lovett , J E , Han , S & Sherwin , M S 2023 , ' Triggered functional dynamics of AsLOV2 by time-resolved electron paramagnetic resonance at high magnetic fields ' , Angewandte Chemie International Edition , vol. 62 , no. 13 , e202212832 . https://doi.org/10.1002/anie.202212832
Publication
Angewandte Chemie International Edition
Status
Peer reviewed
ISSN
1433-7851Type
Journal article
Description
Funding: The authors would like to acknowledge support from the NSF though grant MCB 2025860 and the UC Office of the President Multicampus Research Programs and Initiatives under MRI-19-601107 for the development of TiGGER and the core research presented here. Biochemical and complementary biophysical studies of AsLOV2 were supported by the NIH MIRA through grant R35GM136411. JEL thanks The Royal Society for a University Research Fellowship.Collections
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