Source 1review2007Photosynthesis Research
Toolkit/EPR spectroscopy
EPR spectroscopy
Also known as: electron paramagnetic resonance spectroscopy
Taxonomy: Technique Branch / Method. Workflows sit above the mechanism and technique branches rather than replacing them.
Summary
FX has been identified in HbRC cores by EPR and Mössbauer spectroscopy... thereby regaining both the 75 ms kinetic phase resulting from P798+ [FA/FB]- recombination and the light-induced EPR resonances of FA- and FB-.
Usefulness & Problems
Why this is useful
EPR spectroscopy is used here to identify the FX cluster and to observe light-induced FA- and FB- resonances in the HbRC system.; identifying iron-sulfur cofactors in heliobacterial reaction-center cores; detecting light-induced resonances associated with FA- and FB-
Source:
EPR spectroscopy is used here to identify the FX cluster and to observe light-induced FA- and FB- resonances in the HbRC system.
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identifying iron-sulfur cofactors in heliobacterial reaction-center cores
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detecting light-induced resonances associated with FA- and FB-
Problem solved
It enables direct spectroscopic support for cofactor assignment and functional reconstitution on the acceptor side.; provides spectroscopic evidence for cofactor identity and acceptor-side functional restoration
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It enables direct spectroscopic support for cofactor assignment and functional reconstitution on the acceptor side.
Source:
provides spectroscopic evidence for cofactor identity and acceptor-side functional restoration
Problem links
provides spectroscopic evidence for cofactor identity and acceptor-side functional restoration
LiteratureIt enables direct spectroscopic support for cofactor assignment and functional reconstitution on the acceptor side.
Source:
It enables direct spectroscopic support for cofactor assignment and functional reconstitution on the acceptor side.
Taxonomy & Function
Primary hierarchy
Technique Branch
Method: A concrete measurement method used to characterize an engineered system.
Mechanisms
electron paramagnetic resonance detection of paramagnetic cofactorslight-induced generation and observation of reduced iron-sulfur cluster statesTechniques
Functional AssayTarget processes
recombinationInput: Light
Implementation Constraints
cofactor dependency: cofactor requirement unknownencoding mode: genetically encodedimplementation constraint: context specific validationimplementation constraint: spectral hardware requirementoperating role: sensor
This method requires EPR instrumentation and prepared HbRC samples capable of producing the relevant paramagnetic states.; requires EPR instrumentation; requires suitable HbRC core preparations and light-induced measurements for the reported use cases
The abstract does not indicate that EPR alone resolves the entire electron-transfer pathway or all kinetic assignments.; the abstract does not provide protocol details or comparative performance against other spectroscopies
Validation
Cell-freeBacteriaMammalianMouseHumanTherapeuticIndep. Replication
Supporting Sources
Ranked Claims
A low-molecular-mass polypeptide containing the terminal FA and FB iron-sulfur clusters was identified in the heliobacterial reaction center and named PshB.
the low molecular mass polypeptide that contains the terminal FA and FB iron-sulfur clusters has been identified... The gene was named 'pshB' and the protein 'PshB'
FX in heliobacterial reaction-center cores was identified by EPR and Mössbauer spectroscopy as a [4Fe-4S]1+,2+ cluster with a ground spin state of S=3/2.
FX has been identified in HbRC cores by EPR and Mössbauer spectroscopy, and shown to be a [4Fe-4S]1+,2+ cluster with a ground spin state of S=3/2.
ground spin state S=3/2
Removal of the FA/FB-containing polypeptide changes flash-induced kinetics from 75 ms to 15 ms, supporting assignment of the 75 ms phase to P798+ [FA/FB]- recombination and the 15 ms phase to P798+ FX- recombination.
The change in the lifetime of the flash-induced kinetics from 75 ms to 15 ms on its removal shows that the former arises from the P798+ [FA/FB]- recombination, and the latter from P798+ FX- recombination.
flash-induced kinetic lifetime 75 msflash-induced kinetic lifetime 15 ms
Expressed PshB can be rebound to isolated heliobacterial reaction-center cores, restoring the 75 ms kinetic phase and light-induced EPR resonances of FA- and FB-.
The expressed protein can be rebound to isolated HbRC cores, thereby regaining both the 75 ms kinetic phase resulting from P798+ [FA/FB]- recombination and the light-induced EPR resonances of FA- and FB-.
restored kinetic phase lifetime 75 ms
Approval Evidence
1 source2 linked approval claimsfirst-pass slug epr-spectroscopy
FX has been identified in HbRC cores by EPR and Mössbauer spectroscopy... thereby regaining both the 75 ms kinetic phase resulting from P798+ [FA/FB]- recombination and the light-induced EPR resonances of FA- and FB-.
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component identificationsupports
FX in heliobacterial reaction-center cores was identified by EPR and Mössbauer spectroscopy as a [4Fe-4S]1+,2+ cluster with a ground spin state of S=3/2.
FX has been identified in HbRC cores by EPR and Mössbauer spectroscopy, and shown to be a [4Fe-4S]1+,2+ cluster with a ground spin state of S=3/2.
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reconstitution effectsupports
Expressed PshB can be rebound to isolated heliobacterial reaction-center cores, restoring the 75 ms kinetic phase and light-induced EPR resonances of FA- and FB-.
The expressed protein can be rebound to isolated HbRC cores, thereby regaining both the 75 ms kinetic phase resulting from P798+ [FA/FB]- recombination and the light-induced EPR resonances of FA- and FB-.
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Comparisons
Source-stated alternatives
The abstract explicitly pairs EPR with Mössbauer spectroscopy and also references flash-induced kinetic measurements and chemical assays.
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The abstract explicitly pairs EPR with Mössbauer spectroscopy and also references flash-induced kinetic measurements and chemical assays.
Source-backed strengths
used in the review to identify FX; used to detect restored FA- and FB- resonances after PshB rebinding
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used in the review to identify FX
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used to detect restored FA- and FB- resonances after PshB rebinding
Compared with assays
The abstract explicitly pairs EPR with Mössbauer spectroscopy and also references flash-induced kinetic measurements and chemical assays.
Shared frame: source-stated alternative in extracted literature
Strengths here: used in the review to identify FX; used to detect restored FA- and FB- resonances after PshB rebinding.
Relative tradeoffs: the abstract does not provide protocol details or comparative performance against other spectroscopies.
Source:
The abstract explicitly pairs EPR with Mössbauer spectroscopy and also references flash-induced kinetic measurements and chemical assays.
Compared with Mössbauer spectroscopy
The abstract explicitly pairs EPR with Mössbauer spectroscopy and also references flash-induced kinetic measurements and chemical assays.
Shared frame: source-stated alternative in extracted literature
Strengths here: used in the review to identify FX; used to detect restored FA- and FB- resonances after PshB rebinding.
Relative tradeoffs: the abstract does not provide protocol details or comparative performance against other spectroscopies.
Source:
The abstract explicitly pairs EPR with Mössbauer spectroscopy and also references flash-induced kinetic measurements and chemical assays.
Ranked Citations
- 1.