University of Sussex
Browse

File(s) not publicly available

Conformational Changes in a Photosensory LOV Domain Monitored by Time-Resolved NMR Spectroscopy

journal contribution
posted on 2023-06-07, 21:04 authored by Shannon M Harper, Lori C Neil, Iain Day, P J Hore, Kevin H Gardner
Phototropins are light-activated kinases from plants that utilize light-oxygen-voltage (LOV) domains as blue light photosensors. Illumination of these domains leads to the formation of a covalent linkage between the protein and an internally bound flavin chromophore, destabilizing the surrounding protein and displacing an a-helix from its surface. Here we use a combination of spectroscopic tools to monitor the kinetic processes that spontaneously occur in the dark as the protein returns to the noncovalent ground state. Using time-resolved two-dimensional (2D) NMR methods, we measured the rate of this process at over 100 independent sites throughout the protein, establishing that regeneration of the dark state occurs cooperatively within a 1.6-fold range of observed rates. These data agree with other spectroscopic measurements of the kinetics of protein/FMN bond cleavage and global conformational changes, consistent with these processes experiencing a common rate-limiting step. Arrhenius analyses of the temperature dependence of these rates suggest that the transition state visited during this regeneration has higher energy than the denatured form of this protein domain despite the fact that there is no global unfolding of the domain during this process.

History

Publication status

  • Published

Journal

Journal of the American Chemical Society

ISSN

0002-7863

Publisher

American Chemical Society

Issue

11

Volume

126

Page range

3390-3391

Pages

2.0

Department affiliated with

  • Chemistry Publications

Notes

ID helped develop idea for real-time NMR monitoring of the recovery of the protein ground state from the photo-excited (signaling) state, and contributed to the analysis of the results. The technique described provides residue-specific kinetic information on the conformational changes occurring in the protein during photoactivation.

Full text available

  • No

Peer reviewed?

  • Yes

Legacy Posted Date

2012-02-06

Usage metrics

    University of Sussex (Publications)

    Categories

    No categories selected

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC