The Role of the 145 Residue in Photochemical Properties of the Biphotochromic Protein mSAASoti: Brightness versus Photoconversion

Alexandra V Gavshina; Ilya D Solovyev; Alexander P Savitsky

doi:10.3390/ijms232416058

The Role of the 145 Residue in Photochemical Properties of the Biphotochromic Protein mSAASoti: Brightness versus Photoconversion

Int J Mol Sci. 2022 Dec 16;23(24):16058. doi: 10.3390/ijms232416058.

Authors

Alexandra V Gavshina¹, Ilya D Solovyev¹, Alexander P Savitsky¹

Affiliation

¹ A. N. Bach Institute of Biochemistry, Federal Research Center "Fundamentals of Biotechnology" of the Russian Academy of Sciences, Leninsky Ave. 33, bld. 2, 119071 Moscow, Russia.

Abstract

Photoswitchable fluorescent proteins (FPs) have become indispensable tools for studying life sciences. mSAASoti FP, a biphotochromic FP, is an important representative of this protein family. We created a series of mSAASoti mutants in order to obtain fast photoswitchable variants with high brightness. K145P mSAASoti has the highest molar extinction coefficient of all SAASoti mutants studied; C21N/K145P/M163A switches to the dark state 36 times faster than mSAASoti, but it lost its ability to undergo green-to-red photoconversion. Finally, the C21N/K145P/F177S and C21N/K145P/M163A/F177S variants demonstrated a high photoswitching rate between both green and red forms.

Keywords: biphotochromic fluorescent proteins; brightness; photochemistry of fluorescent proteins; photoconversion green to red; photoswitching.

MeSH terms

Coloring Agents*
Green Fluorescent Proteins / chemistry
Luminescent Proteins / metabolism

Substances

Luminescent Proteins
Green Fluorescent Proteins
Coloring Agents

Grants and funding

This research was funded by the Ministry of Science and Higher Education of the Russian Federation.