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Updated: Jul 29, 2025
High Precision FRET at Single-molecule Level for Biomolecule Structure Determination
Published on: May 13, 2017
Cryogenic Single-Molecule Fluorescence Detection of the Mid-Infrared Response of an Intrinsic Pigment in a
Kohei Otomo1,2, Takehisa Dewa3, Michio Matsushita1
1Department of Physics, Tokyo Institute of Technology, Meguro, Tokyo 152-8550, Japan.
Abstract:
We observed the mid-infrared (MIR) response of a single pigment of bacteriochlorophyll a at the B800 binding site of a light-harvesting 2 complex. At a temperature of 1.5 K, a single complex in a spatially isolated spot in a near-infrared (NIR) fluorescence image was selected and was simultaneously irradiated with MIR and NIR light. We found that the temporal behavior of the NIR fluorescence excitation spectrum of individual pigments in a single complex was modulated by the MIR irradiation at 1650 cm-1. The MIR modulation of a single pigment was linearly proportional to the MIR intensity. The MIR linear response was detected in the range from 1580 to 1670 cm-1.
