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Electron spin label distance between labels, determination

Fourier Deconvolution. A synthetic 30-residue polypeptide was synthesized as an electron-transfer protein.42 A spin label was attached at position 21 and the distance between the two labels in a dimer was determined by Fourier deconvolution of the CW line-shape in frozen solution. Based on the known geometry of the label, it was calculated that the interspin distance of 22.5 A corresponded to 13.5 + 0.9 A between the Ca carbons on the two polypeptide chains. [Pg.323]

Persson, M., Harbridge, J. R., Hammerstrom, P., Mitri, R., Ma rtenson, L-G., Carlson, U., Eaton, G., and Eaton, S. (2001) Comparison of electron paramagnetic resonance methods to determine distances between spin labels on human carbonic anhydrase II, Biophys. J. 80, 2886-2897. [Pg.216]

Stainhoff, H.-J., Radzwill, N., Thevis, W., Lenz, V., Brandenburg, D., Antson, A., Dodson, G., and Wollmer, A. (1997) Determination of interspin distances between spin labels attached to insulin comparison of electron paramagnetic resonance data with the X-ray structure, Biophys. J. 73,3287-3298. [Pg.221]

Abstract Multi-resonance involves ENDOR, TRIPLE and ELDOR in continuous-wave (CW) and pulsed modes. ENDOR is mainly used to increase the spectral resolution of weak hyperfine couplings (hfc). TRIPLE provides a method to determine the signs of the hfc. The ELDOR method uses two microwave (MW) frequencies to obtain distances between specific spin-labeled sites in pulsed experiments, PELDOR or DEER. The electron-spin-echo (ESE) technique involves radiation with two or more MW pulses. The electron-spin-echo-envelope-modulation (ESEEM) method is particularly used to resolve weak anisotropic hfc in disordered solids. HYSCORE (Hyperfine Sublevel Correlation Spectroscopy) is the most common two-dimensional ESEEM method to measure weak hfc after Fourier transformation of the echo decay signal. The ESEEM and HYSCORE methods are not applicable to liquid samples, in which case the FID (free induction decay) method finds some use. Pulsed ESR is also used to measure magnetic relaxation in a more direct way than with CW ESR. [Pg.29]

Radicals normally do not occur in peptides but they can be generated by irradiation at low temperature with UV, electrons or X-rays, usually at the a-carbon atom, and then can be recognized by ESR. There are some radicals that are stable at ambient temperature, for instance N-oxides with the structural element C-NO-C. In biochemistry, e.g. derivatives of 2,2,5,5-tetramethyl-pyrrolidine-l-oxide are being used as spin labels, conjugated to bioactive compounds. In this way ESR can localize the position of possible receptor sites. For instance, in hormone research the distances in the neurophysin complex between spin-labeled small peptides, models of oxytocin, have been determined [27]. [Pg.127]

In the past decades, continuous-wave (CW) and pulse [double quantum coherence (DQC) and PELDOR] ESR spectra of double-spin-labeled systems have been reported [90, 91]. The high sensitivity provided by DQC and PELDOR spectra [92] allows reliable determination of distances (1.6-6.0 nm) between labels in frozen solution but cannot be used for distances shorter than 1.6 nm because of the large electron dipolar interaction and the presence of relevant scalar electron exchange interactions prevents the irradiation of a single electron spin, which is a prerequisite for their application [92]. [Pg.235]


See other pages where Electron spin label distance between labels, determination is mentioned: [Pg.40]    [Pg.2560]    [Pg.213]    [Pg.2559]    [Pg.97]    [Pg.330]    [Pg.239]    [Pg.305]    [Pg.184]    [Pg.394]    [Pg.199]   
See also in sourсe #XX -- [ Pg.604 ]




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Distance between spin labels, determination

Electron distance

Electron spin label

Electron spin labeling

Spin labelling

Spin-labeled

Spin-labels

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