Gavshina AV, Solovyev ID, Savitsky AP. The Role of the 145 Residue in Photochemical Properties of the Biphotochromic Protein mSAASoti: Brightness versus Photoconversion.
Int J Mol Sci 2022;
23:ijms232416058. [PMID:
36555699 PMCID:
PMC9787662 DOI:
10.3390/ijms232416058]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 12/06/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022] Open
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.
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