scholarly journals SLIM: A Short‐Linked, Highly Redox‐Stable Trityl Label for High‐Sensitivity In‐Cell EPR Distance Measurements

2020 ◽  
Vol 59 (24) ◽  
pp. 9767-9772 ◽  
Author(s):  
Nico Fleck ◽  
Caspar A. Heubach ◽  
Tobias Hett ◽  
Florian R. Haege ◽  
Pawel P. Bawol ◽  
...  
Keyword(s):  
High Sensitivity ◽  
Distance Measurements

High Sensitivity In-Cell EPR Distance Measurements on Proteins using an Optimized Gd(III) Spin Label

2018 ◽  
Vol 9 (20) ◽  
pp. 6119-6123 ◽  
Author(s):  
Yin Yang ◽  
Feng Yang ◽  
Yan-Jun Gong ◽  
Thorsten Bahrenberg ◽  
Akiva Feintuch ◽  
...  
Keyword(s):  
Spin Label ◽  
High Sensitivity ◽  
Distance Measurements

scholarly journals SLIM: A Short‐Linked, Highly Redox‐Stable Trityl Label for High‐Sensitivity In‐Cell EPR Distance Measurements

2020 ◽  
Vol 132 (24) ◽  
pp. 9854-9859 ◽  
Author(s):  
Nico Fleck ◽  
Caspar A. Heubach ◽  
Tobias Hett ◽  
Florian R. Haege ◽  
Pawel P. Bawol ◽  
...  
Keyword(s):  
High Sensitivity ◽  
Distance Measurements

Gadolinium(III) Spin Labels for High-Sensitivity Distance Measurements in Transmembrane Helices

2013 ◽  
Vol 125 (45) ◽  
pp. 12047-12050 ◽  
Author(s):  
Erez Matalon ◽  
Thomas Huber ◽  
Gregor Hagelueken ◽  
Bim Graham ◽  
Veronica Frydman ◽  
...  
Keyword(s):  
High Sensitivity ◽  
Spin Labels ◽  
Transmembrane Helices ◽  
Distance Measurements

scholarly journals High sensitivity Gd<sup>3+</sup>-Gd<sup>3+</sup> EPR distance measurements that eliminate artefacts seen at short distances

2020 ◽  
Author(s):  
Hassane El Mkami ◽  
Robert I. Hunter ◽  
Paul A. S. Cruickshank ◽  
Michael J. Taylor ◽  
Janet E. Lovett ◽  
...  
Keyword(s):  
Signal To Noise Ratio ◽  
High Sensitivity ◽  
Frequency Separation ◽  
Spin Labels ◽  
Distance Measurements ◽  
Flip Flop ◽  
Central Transition ◽  
High Modulation ◽  
Distance Distributions ◽  
Double Electron Electron Resonance

Abstract. Gadolinium complexes are attracting increasing attention as spin labels for EPR dipolar distance measurements in biomolecules and particularly for in-cell measurements. It has been shown that flip-flop transitions within the central transition of the high spin Gd3+ ion can introduce artefacts in dipolar distance measurements, particularly when measuring distances less than 3–4 nm. Previous work has shown some reduction of these artefacts through increasing the frequency separation between the two frequencies required for the Double Electron-Electron Resonance (DEER) experiment. Here we use a high power (1 kW), wideband, non-resonant, system operating at 94 GHz to evaluate DEER measurement protocols using two rigid Gd(III)-rulers, consisting of two [GdIII(PyMTA)] complexes, with separations of 2.1 nm and 6.0 nm, respectively. We show that by avoiding the |−1/2⟩ → |1/2⟩ central transition completely, and placing both the pump and the observer pulses on either side of the central transition, we can now observe apparently artefact-free spectra and narrow distance distributions, even for a Gd-Gd distance of 2.1 nm. Importantly we still maintain excellent signal-to-noise ratio and relatively high modulation depths. These results have implications for in-cell EPR measurements at naturally occurring biomolecule concentrations.

scholarly journals High-sensitivity Gd<sup>3+</sup>–Gd<sup>3+</sup> EPR distance measurements that eliminate artefacts seen at short distances

2020 ◽  
Vol 1 (2) ◽  
pp. 301-313
Author(s):  
Hassane EL Mkami ◽  
Robert I. Hunter ◽  
Paul A. S. Cruickshank ◽  
Michael J. Taylor ◽  
Janet E. Lovett ◽  
...  
Keyword(s):  
Signal To Noise Ratio ◽  
High Sensitivity ◽  
Frequency Separation ◽  
Spin Labels ◽  
Distance Measurements ◽  
Flip Flop ◽  
Central Transition ◽  
High Modulation ◽  
Distance Distributions ◽  
Double Electron Electron Resonance

Abstract. Gadolinium complexes are attracting increasing attention as spin labels for EPR dipolar distance measurements in biomolecules and particularly for in-cell measurements. It has been shown that flip-flop transitions within the central transition of the high-spin Gd3+ ion can introduce artefacts in dipolar distance measurements, particularly when measuring distances less than 3 nm. Previous work has shown some reduction of these artefacts through increasing the frequency separation between the two frequencies required for the double electron–electron resonance (DEER) experiment. Here we use a high-power (1 kW), wideband, non-resonant system operating at 94 GHz to evaluate DEER measurement protocols using two stiff Gd(III) rulers, consisting of two bis-Gd3+–PyMTA complexes, with separations of 2.1 nm and 6.0 nm, respectively. We show that by avoiding the -12→12 central transition completely, and placing both the pump and the observer pulses on either side of the central transition, we can now observe apparently artefact-free spectra and narrow distance distributions, even for a Gd–Gd distance of 2.1 nm. Importantly we still maintain excellent signal-to-noise ratio and relatively high modulation depths. These results have implications for in-cell EPR measurements at naturally occurring biomolecule concentrations.

scholarly journals Supplementary material to "High sensitivity Gd<sup>3+</sup>-Gd<sup>3+</sup> EPR distance measurements that eliminate artefacts seen at short distances"

2020 ◽  
Author(s):  
Hassane El Mkami ◽  
Robert I. Hunter ◽  
Paul A. S. Cruickshank ◽  
Michael J. Taylor ◽  
Janet E. Lovett ◽  
...  
Keyword(s):  
High Sensitivity ◽  
Distance Measurements ◽  
Supplementary Material

Gadolinium(III) Spin Labels for High-Sensitivity Distance Measurements in Transmembrane Helices

2013 ◽  
Vol 52 (45) ◽  
pp. 11831-11834 ◽  
Author(s):  
Erez Matalon ◽  
Thomas Huber ◽  
Gregor Hagelueken ◽  
Bim Graham ◽  
Veronica Frydman ◽  
...  
Keyword(s):  
High Sensitivity ◽  
Spin Labels ◽  
Transmembrane Helices ◽  
Distance Measurements

Radio Measurements of Coronal Magnetic Fields

1994 ◽  
Vol 144 ◽  
pp. 21-28 ◽  
Author(s):  
G. B. Gelfreikh
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Solar Corona ◽  
Active Regions ◽  
High Sensitivity ◽  
Coronal Magnetic Field ◽  
Transverse Magnetic ◽  
Radio Sources ◽  
Radio Waves ◽  
Solar Active Regions

AbstractA review of methods of measuring magnetic fields in the solar corona using spectral-polarization observations at microwaves with high spatial resolution is presented. The methods are based on the theory of thermal bremsstrahlung, thermal cyclotron emission, propagation of radio waves in quasi-transverse magnetic field and Faraday rotation of the plane of polarization. The most explicit program of measurements of magnetic fields in the atmosphere of solar active regions has been carried out using radio observations performed on the large reflector radio telescope of the Russian Academy of Sciences — RATAN-600. This proved possible due to good wavelength coverage, multichannel spectrographs observations and high sensitivity to polarization of the instrument. Besides direct measurements of the strength of the magnetic fields in some cases the peculiar parameters of radio sources, such as very steep spectra and high brightness temperatures provide some information on a very complicated local structure of the coronal magnetic field. Of special interest are the results found from combined RATAN-600 and large antennas of aperture synthesis (VLA and WSRT), the latter giving more detailed information on twodimensional structure of radio sources. The bulk of the data obtained allows us to investigate themagnetospheresof the solar active regions as the space in the solar corona where the structures and physical processes are controlled both by the photospheric/underphotospheric currents and surrounding “quiet” corona.

Backscattered Electron Imaging of GaAs/AlGaAs Super Lattice Structures with an Ultra-High- Resolution SEM

1988 ◽  
Vol 46 ◽  
pp. 204-205
Author(s):  
Kazumichi Ogura ◽  
Michael M. Kersker
Keyword(s):  
High Resolution ◽  
Layer Structure ◽  
High Sensitivity ◽  
Beam Current ◽  
Electron Beam Current ◽  
Lattice Structures ◽  
Super Lattice ◽  
Different Types ◽  
Backscattered Electron ◽  
Electron Imaging

Backscattered electron (BE) images of GaAs/AlGaAs super lattice structures were observed with an ultra high resolution (UHR) SEM JSM-890 with an ultra high sensitivity BE detector. Three different types of super lattice structures of GaAs/AlGaAs were examined. Each GaAs/AlGaAs wafer was cleaved by a razor after it was heated for approximately 1 minute and its crosssectional plane was observed.First, a multi-layer structure of GaAs (100nm)/AlGaAs (lOOnm) where A1 content was successively changed from 0.4 to 0.03 was observed. Figures 1 (a) and (b) are BE images taken at an accelerating voltage of 15kV with an electron beam current of 20pA. Figure 1 (c) is a sketch of this multi-layer structure corresponding to the BE images. The various layers are clearly observed. The differences in A1 content between A1 0.35 Ga 0.65 As, A1 0.4 Ga 0.6 As, and A1 0.31 Ga 0.69 As were clearly observed in the contrast of the BE image.

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