Color Tuning in a Green-Shifted Red Fluorescent Protein Variant GmKate
Author Information
Author(s): Wang Qi, Byrnes Laura J., Shui Bo, Röhrig Ute F., Singh Avtar, Chudakov Dmitriy M., Lukyanov Sergey, Zipfel Warren R., Kotlikoff Michael I., Sondermann Holger
Primary Institution: Cornell University
Hypothesis
Can mutations in mKate lead to a green-shifted red fluorescent protein variant with pH-dependent color conversion?
Conclusion
The study identifies GmKate as a pH-dependent fluorescent protein that can switch colors from green to red based on protonation states.
Supporting Evidence
- GmKate exhibits pH-dependent fluorescence with distinct absorbance and emission peaks.
- At physiological pH, GmKate emits green fluorescence, while at high pH, it emits far-red fluorescence.
- Crystal structures reveal the molecular basis for the color transition.
- Quantum chemical calculations confirm the role of protonation states in color tuning.
Takeaway
Scientists made a special protein that changes color depending on how acidic or basic it is, which can help in studying cells better.
Methodology
The study involved introducing mutations into mKate, followed by biochemical analysis and structural characterization through crystallography.
Limitations
The brightness of GmKate is lower compared to other fluorescent proteins, which may limit its application as a pH sensor.
Digital Object Identifier (DOI)
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