A Modified Infrared Spectrometer with High Time Resolution and Its Application for Investigating Fast Conformational Changes of the GTPase Ras

Lin, Jie; Gerwert, Klaus; Kötting, Carsten

doi:10.1366/13-07320

Cited by 10 publications

(10 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…7). Achieving ns time resolution also required a redesigned method for fast detection of absorbance change of a suitable IR band, in this case the γ‐phosphate band for RASGTP in the “on” state at 1142 cm −1 (49). For comparison, the lower limit for rapid scan FTIR is shown by the yellow line in Fig.…”

Section: Representative Applicationsmentioning

confidence: 99%

The Discovery, Development and Demonstration of Three Caged Compounds^†

Steinmetz

Givens

2021

Photochem & Photobiology

View full text Add to dashboard Cite

An overview of the history, mechanistic aspects and applications is provided for p-hydroxyphenacyl (pHP) and benzoin photoremovable protecting groups, which release biologically important leaving groups upon photolysis with UV light. Also discussed is (7-diethylaminocoumarin-4-yl)methyl (DEACM), a photoremovable protecting group that absorbs visible light. These are followed by the a-keto amides and naphtho-and benzothiophene-2-carboxanilides as caging groups, which eliminate leaving groups via photochemically produced zwitterionic intermediates. Also covered are amino-1,4benzoquinones, which upon exposure to green and red wavelengths of light photorearrange to an unstable photoproduct that subsequently eliminates leaving groups in aqueous media. Selected examples are given that use these photoremovable protecting (caging) groups for the light-activated release of biologically important substrates under physiological conditions in cells and tissue as practical applications in biology, biochemistry and physiology. These caging groups have found significant applications because their photochemistry is efficient and a single coproduct is formed in addition to the photoreleased substrate.

show abstract

Section: Representative Applicationsmentioning

confidence: 99%

The Discovery, Development and Demonstration of Three Caged Compounds^†

Steinmetz

Givens

2021

Photochem & Photobiology

View full text Add to dashboard Cite

show abstract

“…Time-resolved infrared spectroscopy takes advantage of laser light sources. For example, a PbS diode laser has been used to record conformational changes of the Ras protein in the nanosecond time regime with a flash-photolysis set-up (Lin et al, 2014 ). The intensity of the laser beam was measured, after passing through the sample, by an infrared detector.…”

Section: Spectroscopy With Lasersmentioning

confidence: 99%

Time-resolved infrared spectroscopic techniques as applied to channelrhodopsin

Ritter

Puškar

Bartl

et al. 2015

Front. Mol. Biosci.

View full text Add to dashboard Cite

Among optogenetic tools, channelrhodopsins, the light gated ion channels of the plasma membrane from green algae, play the most important role. Properties like channel selectivity, timing parameters or color can be influenced by the exchange of selected amino acids. Although widely used, in the field of neurosciences for example, there is still little known about their photocycles and the mechanism of ion channel gating and conductance. One of the preferred methods for these studies is infrared spectroscopy since it allows observation of proteins and their function at a molecular level and in near-native environment. The absorption of a photon in channelrhodopsin leads to retinal isomerization within femtoseconds, the conductive states are reached in the microsecond time scale and the return into the fully dark-adapted state may take more than minutes. To be able to cover all these time regimes, a range of different spectroscopical approaches are necessary. This mini-review focuses on time-resolved applications of the infrared technique to study channelrhodopsins and other light triggered proteins. We will discuss the approaches with respect to their suitability to the investigation of channelrhodopsin and related proteins.

show abstract

“…2,4 Pump-probe experiments (vis-pump and IR probe) even allow for femtosecond time-resolved IR spectroscopy. 5 However, samples that allow only single excitations can either be measured only at a single wavelength 6 or with rapid-scan FTIR. 7 The time-resolution of rapid-scan FTIR depends on the scanning velocity of the Michelson interferometer and is limited to about 10 ms at a wavelength resolution of 16 cm −1 within high end research FTIR instruments.…”

Section: Introductionmentioning

confidence: 99%

Microsecond resolved infrared spectroscopy on non-repetitive protein reactions by applying caged-compounds and quantum cascade laser frequency combs

Norahan

Horvath²,

Woitzik

et al. 2021

Preprint

Self Cite

View full text Add to dashboard Cite

Infrared spectroscopy is ideally suited for the investigation of protein reactions at the atomic level. Many systems were investigated successfully by applying Fourier transform infrared (FTIR) spectroscopy. While rapid-scan FTIR spectroscopy is limited by time resolution (about10 ms with 16 cm−1 resolution), step-scan FTIR spectroscopy reaches a time-resolution of about 10 ns but is limited to cyclic reactions that can be repeated hundreds of times under identical conditions. Consequently, FTIR with high time resolution was only possible with photoactivable proteins that undergo a photocycle. The huge number of non-repetitive reactions, e.g. induced by caged compounds, were limited to the ms time domain. The advent of dual comb quantum cascade laser allows now for a rapid reaction monitoring in the μs time domain. Here we investigate the potential to apply such an instrument to the huge class of G-proteins. We compare caged-compound induced reactions monitored by FTIR and dual comb spectroscopy, respectively, by applying the new technique to the α subunit of the inhibiting Gi protein and to the larger protein-protein complex of Gαi with its cognate regulator of G-protein signaling (RGS). We observe good data quality with 4 μs time resolution with a wavelength resolution comparable to FTIR. This is more than three orders of magnitude faster than any FTIR measurement on G-proteins in the literature. This study paves the way for infrared spectroscopic studies in the so far unresolvable μs time regime for non-repetitive biological systems including all GTPases and ATPases.

show abstract

A Modified Infrared Spectrometer with High Time Resolution and Its Application for Investigating Fast Conformational Changes of the GTPase Ras

Cited by 10 publications

References 27 publications

The Discovery, Development and Demonstration of Three Caged Compounds^†

The Discovery, Development and Demonstration of Three Caged Compounds^†

Time-resolved infrared spectroscopic techniques as applied to channelrhodopsin

Microsecond resolved infrared spectroscopy on non-repetitive protein reactions by applying caged-compounds and quantum cascade laser frequency combs

Contact Info

Product

Resources

About

A Modified Infrared Spectrometer with High Time Resolution and Its Application for Investigating Fast Conformational Changes of the GTPase Ras

Cited by 10 publications

References 27 publications

The Discovery, Development and Demonstration of Three Caged Compounds†

The Discovery, Development and Demonstration of Three Caged Compounds†

Time-resolved infrared spectroscopic techniques as applied to channelrhodopsin

Microsecond resolved infrared spectroscopy on non-repetitive protein reactions by applying caged-compounds and quantum cascade laser frequency combs

Contact Info

Product

Resources

About

The Discovery, Development and Demonstration of Three Caged Compounds^†

The Discovery, Development and Demonstration of Three Caged Compounds^†