Related Experiment Video
Updated: May 27, 2026

Atomic Force Microscopy of Red-Light Photoreceptors Using PeakForce Quantitative Nanomechanical Property Mapping
Published on: October 24, 2014
On the collective nature of phytochrome photoactivation
Chen Song1, Georgios Psakis, Christina Lang
1Leids Instituut voor Chemisch Onderzoek, Universiteit Leiden, 2300 RA Leiden, The Netherlands.
Abstract:
The red/far-red-sensing biological photoreceptor phytochrome is a paradigmatic two-state signaling system. The two thermally stable states are interconverted via a photoreaction of the covalently bound tetrapyrrole chromophore. Applying recently developed solid-state nuclear magnetic resonance, we study both the chromophore and its protein pocket in the Pr (red-absorbing) and Pfr (far-red-absorbing) states. The observations show that the phototransformation combines local chemical reactions with a mesoscopic transition of order. Both the chromophore and its binding pocket are quasi-liquid and disordered in Pr, yet quasi-solid and ordered in Pfr. Possible biochemical implications are discussed.
More Related Videos
10:10Investigating Tissue- and Organ-specific Phytochrome Responses using FACS-assisted Cell-type Specific Expression Profiling in Arabidopsis thaliana
Published on: May 29, 2010
10:20Evaluation of Photosynthetic Behaviors by Simultaneous Measurements of Leaf Reflectance and Chlorophyll Fluorescence Analyses
Published on: August 9, 2019
Related Concept Videos
Photoreceptors and Plant Responses to Light
Biological Clocks and Seasonal Responses
Cell Signaling in Plants
The Antenna Complex
The Photochemical Reaction Center
Photosystems
Functioning of Photosystems
Photosystems contain many pigment molecules, such as chlorophylls and carotenoids, arranged in a particular organization across two domains — the antenna complex and the reaction center. The main aim of the pigment molecules...