Initial reaction of a red fluorescent protein mCherry affected by photoswitchability under mutations

Atsushi Yabushita^1,2*, Sheng-Ting Hung³, Takayoshi Kobayashi¹

¹Department of Electrophysics, National Yang Ming Chiao Tung University, Hsinchu, Taiwan
²Research Institute of Engineering, Kanagawa University, Yokohama, Kanagawa, Japan
³Department of Physics, National Sun Yat-sen University, Kaohsiung, Taiwan

* Presenter:Atsushi Yabushita, email:yabushita@nycu.edu.tw

A red fluorescent protein, mCherry, is widely used for applications in the field of molecular and cellular biology as a fluorescent tag and reporter. It is a highly popular and valuable tool due to its advantageous properties, which include its monomeric nature, high photostability, and rapid maturation. Emission at relatively long wavelength of red in visible spectral region is beneficial because there is generally less background autofluorescence in biological samples. Additionally, longer wavelengths of light are less phototoxic to living cells and can penetrate tissues more effectively, which is ideal for live-cell and in vivo imaging. Mutations on mCherry makes it to be reversibly switchable fluorescent protein of rsCherryRev. Irradiation of NUV light at 450 nm light keeps rsCherryRev to be ON state, which can emit fluorescence. Irradiation of yellow light at 550 nm changes it to be OFF state not emitting fluorescence.
The present work performs ultrafast transient absorption (TA) spectroscopy using 10fs broadband visible pulse laser for these two samples of mCherry and rsCherryRev. During the measurement, rsCherryRev sample was measured in two conditions irradiating and not irradiating the NUV light. The difference of the result indicates that the initial reaction of mCherry is affected by mutation and irradiation of NUV light.

Keywords: ultrafast spectroscopy, fluorescent protein, ultrashort pulse laser