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Updated: Feb 17, 2026

Purification and Reconstitution of TRPV1 for Spectroscopic Analysis
Published on: July 3, 2018
Conformational dynamics in TRPV1 channels reported by an encoded coumarin amino acid
Ximena Steinberg1, Marina A Kasimova2, Deny Cabezas-Bratesco1
1Physiology Department, Faculty of Medicine, Universidad Austral de Chile, Valdivia, Chile.
Abstract:
TRPV1 channels support the detection of noxious and nociceptive input. Currently available functional and structural data suggest that TRPV1 channels have two gates within their permeation pathway: one formed by a 'bundle-crossing' at the intracellular entrance and a second constriction at the selectivity filter. To describe conformational changes associated with channel gating, the fluorescent non-canonical amino acid coumarin-tyrosine was genetically encoded at Y671, a residue proximal to the selectivity filter. Total internal reflection fluorescence microscopy was performed to image the conformational dynamics of the channels in live cells. Photon counts and optical fluctuations from coumarin encoded within TRPV1 tetramers correlates with channel activation by capsaicin, providing an optical marker of conformational dynamics at the selectivity filter. In agreement with the fluorescence data, molecular dynamics simulations display alternating solvent exposure of Y671 in the closed and open states. Overall, the data point to a dynamic selectivity filter that may serve as a gate for permeation.
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