Volume 132, Issue 4 pp. 1661-1669
Forschungsartikel

Dual Illumination Enhances Transformation of an Engineered Green-to-Red Photoconvertible Fluorescent Protein

Taylor D. Krueger

Taylor D. Krueger

Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, OR, 97331 USA

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Dr. Longteng Tang

Dr. Longteng Tang

Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, OR, 97331 USA

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Dr. Liangdong Zhu

Dr. Liangdong Zhu

Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, OR, 97331 USA

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Isabella L. Breen

Isabella L. Breen

School of Molecular Sciences, Center for Bioenergy and Photosynthesis, Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, AZ, 85287 USA

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Prof. Dr. Rebekka M. Wachter

Prof. Dr. Rebekka M. Wachter

School of Molecular Sciences, Center for Bioenergy and Photosynthesis, Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, AZ, 85287 USA

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Prof. Dr. Chong Fang

Corresponding Author

Prof. Dr. Chong Fang

Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, OR, 97331 USA

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First published: 06 November 2019
Citations: 3

Abstract

The molecular mechanisms for the photoconversion of fluorescent proteins remain elusive owing to the challenges of monitoring chromophore structural dynamics during the light-induced processes. We implemented time-resolved electronic and stimulated Raman spectroscopies to reveal two hidden species of an engineered ancestral GFP-like protein LEA, involving semi-trapped protonated and trapped deprotonated chromophores en route to photoconversion in pH 7.9 buffer. A new dual-illumination approach was examined, using 400 and 505 nm light simultaneously to achieve faster conversion and higher color contrast. Substitution of UV irradiation with visible light benefits bioimaging, while the spectral benchmark of a trapped chromophore with characteristic ring twisting and bridge-H bending motions enables rational design of functional proteins. With the improved H-bonding network and structural motions, the photoexcited chromophore could increase the photoswitching-aided photoconversion while reducing trapped species.

Conflict of interest

The authors declare no conflict of interest.

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