6533b82efe1ef96bd1293c16
RESEARCH PRODUCT
Thermal Isomerization Mechanism in Dronpa and Its Mutants.
Kirill ZinovjevDaryna SmyrnovaArnout CeulemansIñaki Tuñónsubject
Protein Conformation alpha-HelicalMutantGreen Fluorescent ProteinsGlycineMolecular Dynamics Simulation010402 general chemistryPhotochemistry01 natural sciencesQM/MMDronpaIsomerismLeucine0103 physical sciencesThermalMaterials ChemistryPoint MutationPhysical and Theoretical Chemistrychemistry.chemical_classification010304 chemical physicsChemistryTemperatureValineChromophoreFluorescence0104 chemical sciencesSurfaces Coatings and FilmsAmino acidKineticsThermodynamicsIsomerizationdescription
The photoswitching speed of the reversibly switchable fluorescent proteins (RSFPs) from the family of green fluorescent proteins (GFPs) changes upon mutation which is of direct importance for various high-resolution techniques. Dronpa is one of the most used RSFPs. Its point mutants rsFastLime (Dronpa V157G) and rsKame (Dronpa V157L) exhibit a striking difference in their photoswitching speed. Here the QM/MM on-the-fly string method is used in order to explore the details of the thermal isomerization mechanism. The four principal ways in which isomerization may occur have been scrutinized for each of the three proteins. It has been shown that thermal isomerization occurs via a one-bond-flip mechanism in all three proteins, although, in rsKame, where the chromophore is constrained more, the activation free energy difference between hula-twist and one-bond-flip is significantly smaller. Functional mode analysis has been applied to examine the motions of the amino acids during the isomerization. It clearly identifies the importance of Val/Leu 157 as well as the amino acids in the α-helix during the isomerization.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2016-12-08 | The journal of physical chemistry. B |