학술논문

Chromophore reduction plus reversible photobleaching: how the mKate2 "photoconversion" works.
Document Type
Article
Source
Photochemical & Photobiological Sciences. Jun2021, Vol. 20 Issue 6, p791-803. 13p.
Subject
*FLUORESCENT proteins
*BLEACHING (Chemistry)
*FLUORIMETRY
*TIME-resolved spectroscopy
*ABSORPTION spectra
*FLUORESCENCE spectroscopy
*SODIUM dithionite
Language
ISSN
1474-905X
Abstract
mKate red-to-green photoconversion is a non-canonical type of phototransformation in fluorescent proteins, with a poorly understood mechanism. We have hypothesized that the daughter mKate2 protein may also be photoconvertible, and that this phenomenon would be connected with mKate(2) chromophore photoreduction. Indeed, upon the intense irradiation of the protein sample supplemented by sodium dithionite, the accumulation of green as well as blue spectral forms is enhanced. The reaction was shown to be reversible upon the reductant's removal. However, an analysis of the fluorescence microscopy data, absorption spectra, kinetics and time-resolved fluorescence spectroscopy revealed that the short-wavelength spectral forms of mKate(2) exist before photoactivation, that their fractions increase light-independently after dithionite addition, and that the conversion is facilitated by the photobleaching of the red chromophore form. [ABSTRACT FROM AUTHOR]