1. Regulation of Absorption and Emission in a Protein/Fluorophore Complex.
- Author
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Santos EM, Chandra I, Assar Z, Sheng W, Ghanbarpour A, Bingham C, Vasileiou C, Geiger JH, and Borhan B
- Subjects
- Humans, Retinol-Binding Proteins, Cellular metabolism, Retinol-Binding Proteins, Cellular chemistry, Protein Binding, Protein Engineering, Fluorescent Dyes chemistry
- Abstract
Human cellular retinol binding protein II (hCRBPII) was used as a protein engineering platform to rationally regulate absorptive and emissive properties of a covalently bound fluorogenic dye. We demonstrate the binding of a thio-dapoxyl analog via formation of a protonated imine between an active site lysine residue and the chromophore's aldehyde. Rational manipulation of the electrostatics of the binding pocket results in a 204 nm shift in absorption and a 131 nm shift in emission. The protein is readily expressed in mammalian systems and binds with exogenously delivered fluorophore as demonstrated by live-cell imaging experiments.
- Published
- 2024
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