Saturation-recovery EPR

Here x from Equation 10.4 is changed to the two-membrane domain FOT and SLOT with the depth fixed (the same spin label is distributed between the FOT and SLOT domains). W(FOT) and W(SLOT) are oxygen transport parameters in each domain and represent the collision rate in samples equilibrated with air. Figure 10.9 illustrates the basis of the discrimination by oxygen transport (DOT) method, showing saturation-recovery EPR signals for 5-SASL in membranes... 

When tr is sufficiently long, cw EPR spectra become insensitive to nitroxide motion, and the spectra are indistinguishable from powder patterns. Thus, one must rely on spectroscopic methods beyond cw EPR for the extraction of motional processes. Historically, the motional regime between 1(K) nsec and 1 psec has presented a blind spot to EPR spectroscopy, and reliable methods for extraction of t did not exist. More recently, though, this problem has been solved. The technique combines the methods of pulsed saturation recovery EPR (SR-EPR) and pulsed saturation recovery electron-electron double resonance (SR-ELDOR). Spectroscopic saturation occurs when the applied radiation is sufficiently intense... 

Pyka J, Ibiicki J, Altenbach C, Hubbell WL, Froncisz W (2005) Accessibility and dynamics of nitroxide side chains in T4 lysozyme measured by saturation recovery EPR. Biophys J 89 (3) 2059-2068... 

MacArthur R, Sazinsky MH, Kuhne H, Whittington DA, Lippard SJ, Brudvig GW. 2002. Component B binding to the soluble methane monooxygenase hydroxylase by saturation-recovery EPR spectroscopy of spin-labeled MMOB. J Am Chem Soc 124(45) 13392-13393. 

GaUi C, Atta M, Andersson KK, Graslund A, Brudvig GW. 1995. Variations of the diferric exchange coupling in the R2 subunit of ribonucleotide reductase from four species as determined by saturation-recovery EPR spectroscopy. J Am Chem Soc 117 740-746. 

Zhou Y, Bowler BE, Lynch K, Eaton GR, Eaton SS. 2000. Interspin distances in spin-laheled metmyoglobin variants determined hy saturation recovery EPR. Biophys J 79(2) 1039-1052. 

Hirsh DJ, Beck WF, limes JB, Brudvig GW. 1992. Using saturation recovery EPR to measure distance in proteins. Biochemistry 31(2) 523-541. 

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