Toolkit/time-resolved infrared spectroscopy

time-resolved infrared spectroscopy

Assay Method·Research·Since 2016

Also known as: infrared spectroscopy, time-resolved IR spectroscopy, transient infrared spectroscopy

Taxonomy: Technique Branch / Method. Workflows sit above the mechanism and technique branches rather than replacing them.

Summary

Time-resolved infrared spectroscopy, also termed transient infrared spectroscopy, is a light-triggered functional assay that monitors vibrational and structural dynamics of LOV photoreceptors on picosecond-to-microsecond timescales. In the cited studies, it resolved FMN triplet-state progression to cysteinyl-FMN adduct formation and subsequent protein conformational changes, including Jα helix unfolding.

Usefulness & Problems

Why this is useful

This assay is useful for dissecting ultrafast and early-time photocycles in LOV domains by directly tracking vibrational signatures of chromophore and protein structural states after photoexcitation. The cited work shows that it can compare conserved versus divergent activation steps across AsLOV2, YtvA, EL222, and LovK.

Problem solved

It addresses the problem of measuring how light absorption in LOV photoreceptors is converted into specific chemical intermediates and protein structural responses over picosecond-to-microsecond intervals. The method specifically enables observation of the pathway from the FMN triplet state to cysteinyl adduct formation and the divergence of post-adduct dynamics linked to output function.

Problem links

Limited ability to identify molecular structures through spectroscopy

Gap mapView gap

Time-resolved infrared spectroscopy could help preserve more structural information than simpler static measurements by adding temporal signatures to spectral data. That may make structure inference better constrained, even if it does not itself solve the inverse problem.

Taxonomy & Function

Implementation Constraints

cofactor dependency: cofactor requirement unknownencoding mode: genetically encodedimplementation constraint: context specific validationimplementation constraint: spectral hardware requirementmodality: infrared spectroscopyoperating role: sensortime resolved: True

The assay is light-triggered and was applied to LOV photoreceptors containing FMN, with measurements spanning picoseconds to microseconds. The cited examples include AsLOV2, YtvA, EL222, and LovK, but the supplied evidence does not specify instrument configuration or sample preparation details.

The supplied evidence is limited to LOV photoreceptors and does not establish performance outside this protein family. The evidence also does not provide practical details on spectral resolution, sample requirements, throughput, or compatibility with in vivo measurements.

Validation

Cell-freeBacteriaMammalianMouseHumanTherapeuticIndep. Replication

Supporting Sources

Ranked Claims

Claim 1mechanistic conservationsupports2017Source 3needs review

Across AsLOV2, YtvA, EL222, and LovK, the overall pathway leading to cysteine adduct formation from the FMN triplet state is highly conserved despite differences in tertiary structure.

Despite differences in tertiary structure, the overall pathway leading to cysteine adduct formation from the FMN triplet state is highly conserved, although there are slight variations in rate.
Claim 2mechanistic conservationsupports2017Source 3needs review

Across AsLOV2, YtvA, EL222, and LovK, the overall pathway leading to cysteine adduct formation from the FMN triplet state is highly conserved despite differences in tertiary structure.

Despite differences in tertiary structure, the overall pathway leading to cysteine adduct formation from the FMN triplet state is highly conserved, although there are slight variations in rate.
Claim 3mechanistic conservationsupports2017Source 3needs review

Across AsLOV2, YtvA, EL222, and LovK, the overall pathway leading to cysteine adduct formation from the FMN triplet state is highly conserved despite differences in tertiary structure.

Despite differences in tertiary structure, the overall pathway leading to cysteine adduct formation from the FMN triplet state is highly conserved, although there are slight variations in rate.
Claim 4mechanistic conservationsupports2017Source 3needs review

Across AsLOV2, YtvA, EL222, and LovK, the overall pathway leading to cysteine adduct formation from the FMN triplet state is highly conserved despite differences in tertiary structure.

Despite differences in tertiary structure, the overall pathway leading to cysteine adduct formation from the FMN triplet state is highly conserved, although there are slight variations in rate.
Claim 5mechanistic conservationsupports2017Source 3needs review

Across AsLOV2, YtvA, EL222, and LovK, the overall pathway leading to cysteine adduct formation from the FMN triplet state is highly conserved despite differences in tertiary structure.

Despite differences in tertiary structure, the overall pathway leading to cysteine adduct formation from the FMN triplet state is highly conserved, although there are slight variations in rate.
Claim 6mechanistic conservationsupports2017Source 3needs review

Across AsLOV2, YtvA, EL222, and LovK, the overall pathway leading to cysteine adduct formation from the FMN triplet state is highly conserved despite differences in tertiary structure.

Despite differences in tertiary structure, the overall pathway leading to cysteine adduct formation from the FMN triplet state is highly conserved, although there are slight variations in rate.
Claim 7mechanistic conservationsupports2017Source 3needs review

Across AsLOV2, YtvA, EL222, and LovK, the overall pathway leading to cysteine adduct formation from the FMN triplet state is highly conserved despite differences in tertiary structure.

Despite differences in tertiary structure, the overall pathway leading to cysteine adduct formation from the FMN triplet state is highly conserved, although there are slight variations in rate.
Claim 8mechanistic conservationsupports2017Source 3needs review

Across AsLOV2, YtvA, EL222, and LovK, the overall pathway leading to cysteine adduct formation from the FMN triplet state is highly conserved despite differences in tertiary structure.

Despite differences in tertiary structure, the overall pathway leading to cysteine adduct formation from the FMN triplet state is highly conserved, although there are slight variations in rate.
Claim 9mechanistic conservationsupports2017Source 3needs review

Across AsLOV2, YtvA, EL222, and LovK, the overall pathway leading to cysteine adduct formation from the FMN triplet state is highly conserved despite differences in tertiary structure.

Despite differences in tertiary structure, the overall pathway leading to cysteine adduct formation from the FMN triplet state is highly conserved, although there are slight variations in rate.
Claim 10mechanistic conservationsupports2017Source 3needs review

Across AsLOV2, YtvA, EL222, and LovK, the overall pathway leading to cysteine adduct formation from the FMN triplet state is highly conserved despite differences in tertiary structure.

Despite differences in tertiary structure, the overall pathway leading to cysteine adduct formation from the FMN triplet state is highly conserved, although there are slight variations in rate.
Claim 11post adduct kinetic divergencesupports2017Source 3needs review

After adduct formation, vibrational spectra and kinetics differ significantly among the full-length LOV photoreceptors and are directly linked to the specific output function of the LOV domain.

However, significant differences are observed in the vibrational spectra and kinetics after adduct formation, which are directly linked to the specific output function of the LOV domain.
Claim 12post adduct kinetic divergencesupports2017Source 3needs review

After adduct formation, vibrational spectra and kinetics differ significantly among the full-length LOV photoreceptors and are directly linked to the specific output function of the LOV domain.

However, significant differences are observed in the vibrational spectra and kinetics after adduct formation, which are directly linked to the specific output function of the LOV domain.
Claim 13post adduct kinetic divergencesupports2017Source 3needs review

After adduct formation, vibrational spectra and kinetics differ significantly among the full-length LOV photoreceptors and are directly linked to the specific output function of the LOV domain.

However, significant differences are observed in the vibrational spectra and kinetics after adduct formation, which are directly linked to the specific output function of the LOV domain.
Claim 14post adduct kinetic divergencesupports2017Source 3needs review

After adduct formation, vibrational spectra and kinetics differ significantly among the full-length LOV photoreceptors and are directly linked to the specific output function of the LOV domain.

However, significant differences are observed in the vibrational spectra and kinetics after adduct formation, which are directly linked to the specific output function of the LOV domain.
Claim 15post adduct kinetic divergencesupports2017Source 3needs review

After adduct formation, vibrational spectra and kinetics differ significantly among the full-length LOV photoreceptors and are directly linked to the specific output function of the LOV domain.

However, significant differences are observed in the vibrational spectra and kinetics after adduct formation, which are directly linked to the specific output function of the LOV domain.
Claim 16rate variationsupports2017Source 3needs review

The rate of adduct formation varies by only 3.6-fold among the studied LOV proteins.

While the rate of adduct formation varies by only 3.6-fold among the proteins
adduct formation rate variation 3.6 fold
Claim 17rate variationsupports2017Source 3needs review

The rate of adduct formation varies by only 3.6-fold among the studied LOV proteins.

While the rate of adduct formation varies by only 3.6-fold among the proteins
adduct formation rate variation 3.6 fold
Claim 18rate variationsupports2017Source 3needs review

The rate of adduct formation varies by only 3.6-fold among the studied LOV proteins.

While the rate of adduct formation varies by only 3.6-fold among the proteins
adduct formation rate variation 3.6 fold
Claim 19rate variationsupports2017Source 3needs review

The rate of adduct formation varies by only 3.6-fold among the studied LOV proteins.

While the rate of adduct formation varies by only 3.6-fold among the proteins
adduct formation rate variation 3.6 fold
Claim 20rate variationsupports2017Source 3needs review

The rate of adduct formation varies by only 3.6-fold among the studied LOV proteins.

While the rate of adduct formation varies by only 3.6-fold among the proteins
adduct formation rate variation 3.6 fold
Claim 21rate variationsupports2017Source 3needs review

The rate of adduct formation varies by only 3.6-fold among the studied LOV proteins.

While the rate of adduct formation varies by only 3.6-fold among the proteins
adduct formation rate variation 3.6 fold
Claim 22rate variationsupports2017Source 3needs review

The rate of adduct formation varies by only 3.6-fold among the studied LOV proteins.

While the rate of adduct formation varies by only 3.6-fold among the proteins
adduct formation rate variation 3.6 fold
Claim 23rate variationsupports2017Source 3needs review

The rate of adduct formation varies by only 3.6-fold among the studied LOV proteins.

While the rate of adduct formation varies by only 3.6-fold among the proteins
adduct formation rate variation 3.6 fold
Claim 24rate variationsupports2017Source 3needs review

The rate of adduct formation varies by only 3.6-fold among the studied LOV proteins.

While the rate of adduct formation varies by only 3.6-fold among the proteins
adduct formation rate variation 3.6 fold
Claim 25rate variationsupports2017Source 3needs review

The rate of adduct formation varies by only 3.6-fold among the studied LOV proteins.

While the rate of adduct formation varies by only 3.6-fold among the proteins
adduct formation rate variation 3.6 fold
Claim 26structural change timescalesupports2017Source 3needs review

Large-scale structural changes in the full-length LOV photoreceptors occur over micro- to submillisecond time scales and vary by orders of magnitude depending on output function.

the subsequent large-scale structural changes in the full-length LOV photoreceptors occur over the micro- to submillisecond time scales and vary by orders of magnitude depending on the different output function of each LOV domain.
structural change timescale micro- to submillisecondvariation magnitude orders of magnitude
Claim 27structural change timescalesupports2017Source 3needs review

Large-scale structural changes in the full-length LOV photoreceptors occur over micro- to submillisecond time scales and vary by orders of magnitude depending on output function.

the subsequent large-scale structural changes in the full-length LOV photoreceptors occur over the micro- to submillisecond time scales and vary by orders of magnitude depending on the different output function of each LOV domain.
structural change timescale micro- to submillisecondvariation magnitude orders of magnitude
Claim 28structural change timescalesupports2017Source 3needs review

Large-scale structural changes in the full-length LOV photoreceptors occur over micro- to submillisecond time scales and vary by orders of magnitude depending on output function.

the subsequent large-scale structural changes in the full-length LOV photoreceptors occur over the micro- to submillisecond time scales and vary by orders of magnitude depending on the different output function of each LOV domain.
structural change timescale micro- to submillisecondvariation magnitude orders of magnitude
Claim 29structural change timescalesupports2017Source 3needs review

Large-scale structural changes in the full-length LOV photoreceptors occur over micro- to submillisecond time scales and vary by orders of magnitude depending on output function.

the subsequent large-scale structural changes in the full-length LOV photoreceptors occur over the micro- to submillisecond time scales and vary by orders of magnitude depending on the different output function of each LOV domain.
structural change timescale micro- to submillisecondvariation magnitude orders of magnitude
Claim 30structural change timescalesupports2017Source 3needs review

Large-scale structural changes in the full-length LOV photoreceptors occur over micro- to submillisecond time scales and vary by orders of magnitude depending on output function.

the subsequent large-scale structural changes in the full-length LOV photoreceptors occur over the micro- to submillisecond time scales and vary by orders of magnitude depending on the different output function of each LOV domain.
structural change timescale micro- to submillisecondvariation magnitude orders of magnitude
Claim 31measurementsupports2016Source 2needs review

By 500 μs, the final time-resolved spectrum is essentially identical to the steady-state light-minus-dark FTIR spectrum, indicating that Jα helix unfolding is complete on that time scale.

The final spectrum at 500 μcs is essentially identical to the steady-state light-minus-dark Fourier transform infrared spectrum, indicating that Jα helix unfolding is complete on that time scale.
time to complete Jα helix unfolding 500 μs
Claim 32measurementsupports2016Source 2needs review

By 500 μs, the final time-resolved spectrum is essentially identical to the steady-state light-minus-dark FTIR spectrum, indicating that Jα helix unfolding is complete on that time scale.

The final spectrum at 500 μcs is essentially identical to the steady-state light-minus-dark Fourier transform infrared spectrum, indicating that Jα helix unfolding is complete on that time scale.
time to complete Jα helix unfolding 500 μs
Claim 33measurementsupports2016Source 2needs review

By 500 μs, the final time-resolved spectrum is essentially identical to the steady-state light-minus-dark FTIR spectrum, indicating that Jα helix unfolding is complete on that time scale.

The final spectrum at 500 μcs is essentially identical to the steady-state light-minus-dark Fourier transform infrared spectrum, indicating that Jα helix unfolding is complete on that time scale.
time to complete Jα helix unfolding 500 μs
Claim 34measurementsupports2016Source 2needs review

By 500 μs, the final time-resolved spectrum is essentially identical to the steady-state light-minus-dark FTIR spectrum, indicating that Jα helix unfolding is complete on that time scale.

The final spectrum at 500 μcs is essentially identical to the steady-state light-minus-dark Fourier transform infrared spectrum, indicating that Jα helix unfolding is complete on that time scale.
time to complete Jα helix unfolding 500 μs
Claim 35measurementsupports2016Source 2needs review

By 500 μs, the final time-resolved spectrum is essentially identical to the steady-state light-minus-dark FTIR spectrum, indicating that Jα helix unfolding is complete on that time scale.

The final spectrum at 500 μcs is essentially identical to the steady-state light-minus-dark Fourier transform infrared spectrum, indicating that Jα helix unfolding is complete on that time scale.
time to complete Jα helix unfolding 500 μs
Claim 36measurementsupports2016Source 2needs review

By 500 μs, the final time-resolved spectrum is essentially identical to the steady-state light-minus-dark FTIR spectrum, indicating that Jα helix unfolding is complete on that time scale.

The final spectrum at 500 μcs is essentially identical to the steady-state light-minus-dark Fourier transform infrared spectrum, indicating that Jα helix unfolding is complete on that time scale.
time to complete Jα helix unfolding 500 μs
Claim 37measurementsupports2016Source 2needs review

By 500 μs, the final time-resolved spectrum is essentially identical to the steady-state light-minus-dark FTIR spectrum, indicating that Jα helix unfolding is complete on that time scale.

The final spectrum at 500 μcs is essentially identical to the steady-state light-minus-dark Fourier transform infrared spectrum, indicating that Jα helix unfolding is complete on that time scale.
time to complete Jα helix unfolding 500 μs
Claim 38measurementsupports2016Source 2needs review

By 500 μs, the final time-resolved spectrum is essentially identical to the steady-state light-minus-dark FTIR spectrum, indicating that Jα helix unfolding is complete on that time scale.

The final spectrum at 500 μcs is essentially identical to the steady-state light-minus-dark Fourier transform infrared spectrum, indicating that Jα helix unfolding is complete on that time scale.
time to complete Jα helix unfolding 500 μs
Claim 39measurementsupports2016Source 2needs review

By 500 μs, the final time-resolved spectrum is essentially identical to the steady-state light-minus-dark FTIR spectrum, indicating that Jα helix unfolding is complete on that time scale.

The final spectrum at 500 μcs is essentially identical to the steady-state light-minus-dark Fourier transform infrared spectrum, indicating that Jα helix unfolding is complete on that time scale.
time to complete Jα helix unfolding 500 μs
Claim 40measurementsupports2016Source 2needs review

By 500 μs, the final time-resolved spectrum is essentially identical to the steady-state light-minus-dark FTIR spectrum, indicating that Jα helix unfolding is complete on that time scale.

The final spectrum at 500 μcs is essentially identical to the steady-state light-minus-dark Fourier transform infrared spectrum, indicating that Jα helix unfolding is complete on that time scale.
time to complete Jα helix unfolding 500 μs
Claim 41measurementsupports2016Source 2needs review

By 500 μs, the final time-resolved spectrum is essentially identical to the steady-state light-minus-dark FTIR spectrum, indicating that Jα helix unfolding is complete on that time scale.

The final spectrum at 500 μcs is essentially identical to the steady-state light-minus-dark Fourier transform infrared spectrum, indicating that Jα helix unfolding is complete on that time scale.
time to complete Jα helix unfolding 500 μs
Claim 42measurementsupports2016Source 2needs review

By 500 μs, the final time-resolved spectrum is essentially identical to the steady-state light-minus-dark FTIR spectrum, indicating that Jα helix unfolding is complete on that time scale.

The final spectrum at 500 μcs is essentially identical to the steady-state light-minus-dark Fourier transform infrared spectrum, indicating that Jα helix unfolding is complete on that time scale.
time to complete Jα helix unfolding 500 μs
Claim 43measurementsupports2016Source 2needs review

By 500 μs, the final time-resolved spectrum is essentially identical to the steady-state light-minus-dark FTIR spectrum, indicating that Jα helix unfolding is complete on that time scale.

The final spectrum at 500 μcs is essentially identical to the steady-state light-minus-dark Fourier transform infrared spectrum, indicating that Jα helix unfolding is complete on that time scale.
time to complete Jα helix unfolding 500 μs
Claim 44measurementsupports2016Source 2needs review

By 500 μs, the final time-resolved spectrum is essentially identical to the steady-state light-minus-dark FTIR spectrum, indicating that Jα helix unfolding is complete on that time scale.

The final spectrum at 500 μcs is essentially identical to the steady-state light-minus-dark Fourier transform infrared spectrum, indicating that Jα helix unfolding is complete on that time scale.
time to complete Jα helix unfolding 500 μs
Claim 45measurementsupports2016Source 2needs review

By 500 μs, the final time-resolved spectrum is essentially identical to the steady-state light-minus-dark FTIR spectrum, indicating that Jα helix unfolding is complete on that time scale.

The final spectrum at 500 μcs is essentially identical to the steady-state light-minus-dark Fourier transform infrared spectrum, indicating that Jα helix unfolding is complete on that time scale.
time to complete Jα helix unfolding 500 μs
Claim 46measurementsupports2016Source 2needs review

By 500 μs, the final time-resolved spectrum is essentially identical to the steady-state light-minus-dark FTIR spectrum, indicating that Jα helix unfolding is complete on that time scale.

The final spectrum at 500 μcs is essentially identical to the steady-state light-minus-dark Fourier transform infrared spectrum, indicating that Jα helix unfolding is complete on that time scale.
time to complete Jα helix unfolding 500 μs
Claim 47measurementsupports2016Source 2needs review

By 500 μs, the final time-resolved spectrum is essentially identical to the steady-state light-minus-dark FTIR spectrum, indicating that Jα helix unfolding is complete on that time scale.

The final spectrum at 500 μcs is essentially identical to the steady-state light-minus-dark Fourier transform infrared spectrum, indicating that Jα helix unfolding is complete on that time scale.
time to complete Jα helix unfolding 500 μs
Claim 48measurementsupports2016Source 2needs review

In D2O buffer, covalent cysteinyl-FMN adduct formation in Avena sativa LOV2 occurs in 10 μs.

formation of the covalent cysteinyl-FMN adduct in 10 μcs
cysteinyl-FMN adduct formation time 10 μs
Claim 49measurementsupports2016Source 2needs review

In D2O buffer, covalent cysteinyl-FMN adduct formation in Avena sativa LOV2 occurs in 10 μs.

formation of the covalent cysteinyl-FMN adduct in 10 μcs
cysteinyl-FMN adduct formation time 10 μs
Claim 50measurementsupports2016Source 2needs review

In D2O buffer, covalent cysteinyl-FMN adduct formation in Avena sativa LOV2 occurs in 10 μs.

formation of the covalent cysteinyl-FMN adduct in 10 μcs
cysteinyl-FMN adduct formation time 10 μs
Claim 51measurementsupports2016Source 2needs review

In D2O buffer, covalent cysteinyl-FMN adduct formation in Avena sativa LOV2 occurs in 10 μs.

formation of the covalent cysteinyl-FMN adduct in 10 μcs
cysteinyl-FMN adduct formation time 10 μs
Claim 52measurementsupports2016Source 2needs review

In D2O buffer, covalent cysteinyl-FMN adduct formation in Avena sativa LOV2 occurs in 10 μs.

formation of the covalent cysteinyl-FMN adduct in 10 μcs
cysteinyl-FMN adduct formation time 10 μs
Claim 53measurementsupports2016Source 2needs review

In D2O buffer, FMN singlet-to-triplet conversion in Avena sativa LOV2 occurs in 2 ns.

In D2O buffer, FMN singlet-to-triplet conversion occurs in 2 ns
FMN singlet-to-triplet conversion time 2 ns
Claim 54measurementsupports2016Source 2needs review

In D2O buffer, FMN singlet-to-triplet conversion in Avena sativa LOV2 occurs in 2 ns.

In D2O buffer, FMN singlet-to-triplet conversion occurs in 2 ns
FMN singlet-to-triplet conversion time 2 ns
Claim 55measurementsupports2016Source 2needs review

In D2O buffer, FMN singlet-to-triplet conversion in Avena sativa LOV2 occurs in 2 ns.

In D2O buffer, FMN singlet-to-triplet conversion occurs in 2 ns
FMN singlet-to-triplet conversion time 2 ns
Claim 56measurementsupports2016Source 2needs review

In D2O buffer, FMN singlet-to-triplet conversion in Avena sativa LOV2 occurs in 2 ns.

In D2O buffer, FMN singlet-to-triplet conversion occurs in 2 ns
FMN singlet-to-triplet conversion time 2 ns
Claim 57measurementsupports2016Source 2needs review

In D2O buffer, FMN singlet-to-triplet conversion in Avena sativa LOV2 occurs in 2 ns.

In D2O buffer, FMN singlet-to-triplet conversion occurs in 2 ns
FMN singlet-to-triplet conversion time 2 ns
Claim 58mechanismsupports2016Source 2needs review

Jα helix unfolding in Avena sativa LOV2 proceeds in two steps, with a first phase at 10 μs concomitant with Cys-FMN adduct formation and a second phase at approximately 240 μs.

We observe a two-step unfolding of the Jα helix: The first phase occurs concomitantly with Cys-FMN covalent adduct formation in 10 μcs ... The second phase occurs in approximately 240 μcs.
first Jα helix unfolding phase time 10 μssecond Jα helix unfolding phase time 240 μs
Claim 59mechanismsupports2016Source 2needs review

Jα helix unfolding in Avena sativa LOV2 proceeds in two steps, with a first phase at 10 μs concomitant with Cys-FMN adduct formation and a second phase at approximately 240 μs.

We observe a two-step unfolding of the Jα helix: The first phase occurs concomitantly with Cys-FMN covalent adduct formation in 10 μcs ... The second phase occurs in approximately 240 μcs.
first Jα helix unfolding phase time 10 μssecond Jα helix unfolding phase time 240 μs
Claim 60mechanismsupports2016Source 2needs review

Jα helix unfolding in Avena sativa LOV2 proceeds in two steps, with a first phase at 10 μs concomitant with Cys-FMN adduct formation and a second phase at approximately 240 μs.

We observe a two-step unfolding of the Jα helix: The first phase occurs concomitantly with Cys-FMN covalent adduct formation in 10 μcs ... The second phase occurs in approximately 240 μcs.
first Jα helix unfolding phase time 10 μssecond Jα helix unfolding phase time 240 μs
Claim 61mechanismsupports2016Source 2needs review

Jα helix unfolding in Avena sativa LOV2 proceeds in two steps, with a first phase at 10 μs concomitant with Cys-FMN adduct formation and a second phase at approximately 240 μs.

We observe a two-step unfolding of the Jα helix: The first phase occurs concomitantly with Cys-FMN covalent adduct formation in 10 μcs ... The second phase occurs in approximately 240 μcs.
first Jα helix unfolding phase time 10 μssecond Jα helix unfolding phase time 240 μs
Claim 62mechanismsupports2016Source 2needs review

Jα helix unfolding in Avena sativa LOV2 proceeds in two steps, with a first phase at 10 μs concomitant with Cys-FMN adduct formation and a second phase at approximately 240 μs.

We observe a two-step unfolding of the Jα helix: The first phase occurs concomitantly with Cys-FMN covalent adduct formation in 10 μcs ... The second phase occurs in approximately 240 μcs.
first Jα helix unfolding phase time 10 μssecond Jα helix unfolding phase time 240 μs
Claim 63mechanismsupports2016Source 2needs review

The Avena sativa LOV2 domain binds a C-terminal Jα helix docked on a β-sheet, and the Jα helix unfolds upon light absorption by the FMN chromophore.

The light, oxygen, and voltage 2 (LOV2) sensing domain of plant phototropin binds a C-terminal Jα helix that is docked on a β-sheet and unfolds upon light absorption by the flavin mononucleotide (FMN) chromophore.
Claim 64mechanismsupports2016Source 2needs review

The Avena sativa LOV2 domain binds a C-terminal Jα helix docked on a β-sheet, and the Jα helix unfolds upon light absorption by the FMN chromophore.

The light, oxygen, and voltage 2 (LOV2) sensing domain of plant phototropin binds a C-terminal Jα helix that is docked on a β-sheet and unfolds upon light absorption by the flavin mononucleotide (FMN) chromophore.
Claim 65mechanismsupports2016Source 2needs review

The Avena sativa LOV2 domain binds a C-terminal Jα helix docked on a β-sheet, and the Jα helix unfolds upon light absorption by the FMN chromophore.

The light, oxygen, and voltage 2 (LOV2) sensing domain of plant phototropin binds a C-terminal Jα helix that is docked on a β-sheet and unfolds upon light absorption by the flavin mononucleotide (FMN) chromophore.
Claim 66mechanismsupports2016Source 2needs review

The Avena sativa LOV2 domain binds a C-terminal Jα helix docked on a β-sheet, and the Jα helix unfolds upon light absorption by the FMN chromophore.

The light, oxygen, and voltage 2 (LOV2) sensing domain of plant phototropin binds a C-terminal Jα helix that is docked on a β-sheet and unfolds upon light absorption by the flavin mononucleotide (FMN) chromophore.
Claim 67mechanismsupports2016Source 2needs review

The Avena sativa LOV2 domain binds a C-terminal Jα helix docked on a β-sheet, and the Jα helix unfolds upon light absorption by the FMN chromophore.

The light, oxygen, and voltage 2 (LOV2) sensing domain of plant phototropin binds a C-terminal Jα helix that is docked on a β-sheet and unfolds upon light absorption by the flavin mononucleotide (FMN) chromophore.
Claim 68mechanismsupports2016Source 2needs review

The first phase of Jα helix unfolding is accompanied by rupture of the hydrogen bond between FMN C4=O and Gln-513, motion of the β-sheet, and an additional helical element.

The first phase occurs concomitantly with Cys-FMN covalent adduct formation in 10 μcs, along with hydrogen-bond rupture of the FMN C4═O with Gln-513, motion of the β-sheet, and an additional helical element.
Claim 69mechanismsupports2016Source 2needs review

The first phase of Jα helix unfolding is accompanied by rupture of the hydrogen bond between FMN C4=O and Gln-513, motion of the β-sheet, and an additional helical element.

The first phase occurs concomitantly with Cys-FMN covalent adduct formation in 10 μcs, along with hydrogen-bond rupture of the FMN C4═O with Gln-513, motion of the β-sheet, and an additional helical element.
Claim 70mechanismsupports2016Source 2needs review

The first phase of Jα helix unfolding is accompanied by rupture of the hydrogen bond between FMN C4=O and Gln-513, motion of the β-sheet, and an additional helical element.

The first phase occurs concomitantly with Cys-FMN covalent adduct formation in 10 μcs, along with hydrogen-bond rupture of the FMN C4═O with Gln-513, motion of the β-sheet, and an additional helical element.
Claim 71mechanismsupports2016Source 2needs review

The first phase of Jα helix unfolding is accompanied by rupture of the hydrogen bond between FMN C4=O and Gln-513, motion of the β-sheet, and an additional helical element.

The first phase occurs concomitantly with Cys-FMN covalent adduct formation in 10 μcs, along with hydrogen-bond rupture of the FMN C4═O with Gln-513, motion of the β-sheet, and an additional helical element.
Claim 72mechanismsupports2016Source 2needs review

The first phase of Jα helix unfolding is accompanied by rupture of the hydrogen bond between FMN C4=O and Gln-513, motion of the β-sheet, and an additional helical element.

The first phase occurs concomitantly with Cys-FMN covalent adduct formation in 10 μcs, along with hydrogen-bond rupture of the FMN C4═O with Gln-513, motion of the β-sheet, and an additional helical element.
Claim 73method requirementsupports2015Source 1needs review

A range of different spectroscopical approaches is necessary to cover the full set of channelrhodopsin time regimes from ultrafast photochemistry to slow dark-state recovery.

Claim 74method suitabilitysupports2015Source 1needs review

Infrared spectroscopy is a preferred method for studying channelrhodopsins because it allows observation of proteins and their function at a molecular level and in near-native environment.

Approval Evidence

3 sources3 linked approval claimsfirst-pass slug time-resolved-infrared-spectroscopy
Time-Resolved Infrared Spectroscopy

Source:

investigated using time-resolved infrared spectroscopy from picoseconds to microseconds

Source:

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. This mini-review focuses on time-resolved applications of the infrared technique to study channelrhodopsins and other light triggered proteins.

Source:

measurementsupports

By 500 μs, the final time-resolved spectrum is essentially identical to the steady-state light-minus-dark FTIR spectrum, indicating that Jα helix unfolding is complete on that time scale.

The final spectrum at 500 μcs is essentially identical to the steady-state light-minus-dark Fourier transform infrared spectrum, indicating that Jα helix unfolding is complete on that time scale.

Source:

method requirementsupports

A range of different spectroscopical approaches is necessary to cover the full set of channelrhodopsin time regimes from ultrafast photochemistry to slow dark-state recovery.

Source:

method suitabilitysupports

Infrared spectroscopy is a preferred method for studying channelrhodopsins because it allows observation of proteins and their function at a molecular level and in near-native environment.

Source:

Comparisons

Source-backed strengths

The cited studies indicate that the method captures mechanistic conservation across multiple LOV proteins, showing a highly conserved pathway leading to cysteine adduct formation from the FMN triplet state. It also resolves function-linked divergence after adduct formation and quantified that adduct formation rates varied by only 3.6-fold among the studied proteins.

time-resolved infrared spectroscopy and native green gel system address a similar problem space.

Shared frame: same top-level item type; same primary input modality: light

Strengths here: appears more independently replicated; looks easier to implement in practice.

time-resolved infrared spectroscopy and open-source microplate reader address a similar problem space.

Shared frame: same top-level item type; same primary input modality: light

Strengths here: appears more independently replicated; looks easier to implement in practice.

time-resolved infrared spectroscopy and plant transcriptome profiling address a similar problem space.

Shared frame: same top-level item type; same primary input modality: light

Strengths here: appears more independently replicated; looks easier to implement in practice.

Ranked Citations

  1. 1.
    StructuralSource 1Frontiers in Molecular Biosciences2015Claim 73Claim 74

    Seeded from load plan for claim cl3. Extracted from this source document.

  2. 2.
    StructuralSource 2The Journal of Physical Chemistry Letters2016Claim 31Claim 41Claim 41

    Extracted from this source document.

  3. 3.
    StructuralSource 3Biochemistry2017Claim 10Claim 10Claim 8

    Extracted from this source document.