6533b874fe1ef96bd12d63a3
RESEARCH PRODUCT
Protein dynamics observed by tunable mid-IR quantum cascade lasers across the time range from 10 ns to 1 s
Víctor A. Lórenz-fonfríaVíctor A. Lórenz-fonfríaBernd-joachim SchultzJoachim HeberleHendrik Mohrmannsubject
Time FactorsSpectrophotometry InfraredAbsorption spectroscopyAnalytical chemistry010402 general chemistry53001 natural sciencesMolecular physicsSpectral lineAnalytical Chemistrylaw.inventionchannelrhodopsinflash photolysislawSpectral resolutionAbsorption (electromagnetic radiation)InstrumentationSpectroscopyCarbon MonoxidebiologySpectrometerChemistrybacteriorhodopsinLasers010401 analytical chemistry500 Naturwissenschaften und Mathematik::530 Physik::530 PhysikWaterBacteriorhodopsinLasertime-resolved IR spectroscopyAtomic and Molecular Physics and Optics0104 chemical sciencesSolutionsKineticsCascadeBacteriorhodopsinsmyoglobinbiology.proteinQuantum Theorydescription
We have developed a spectrometer based on tunable quantum cascade lasers (QCLs) for recording time-resolved absorption spectra of proteins in the mid-infrared range. We illustrate its performance by recording time-resolved difference spectra of bacteriorhodopsin in the carboxylic range (1800–1700 cm− 1) and on the CO rebinding reaction of myoglobin (1960–1840 cm− 1), at a spectral resolution of 1 cm− 1. The spectrometric setup covers the time range from 4 ns to nearly a second with a response time of 10–15 ns. Absorption changes as low as 1 × 10− 4 are detected in single-shot experiments at t > 1 μs, and of 5 × 10− 6 in kinetics obtained after averaging 100 shots. While previous time-resolved IR experiments have mostly been conducted on hydrated films of proteins, we demonstrate here that the brilliance of tunable quantum cascade lasers is superior to perform ns time-resolved experiments even in aqueous solution (H2O).
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2017-01-01 |