Very Low-Frequency Broadband Electron Paramagnetic Resonance Spectroscopy of Metalloproteins.

ABSTRACT: A previously developed spectrometer for broadband electron paramagnetic resonance (EPR) spectroscopy of dilute randomly oriented systems has been considerably modified to extend the frequency reach down to the hundred MHz range and to boost concentration sensitivity by 1 to 2 orders of magnitude. The instrument is now suitable for the study of biological systems in particular metalloproteins. As a proof of concept, examples from the class of low-spin ferric hemoproteins are studied in terms of frequency-dependent changes in their EPR spectra. Mono-heme cytochrome c EPR is determined by g-strain over a wide frequency range, whereas a combination of unresolved ligand hyperfine interaction and concentration-dependent intermolecular dipolar interaction becomes dominant at very low frequ

SUBMITTER: Hagen WR 

PROVIDER: S-EPMC8154605 | biostudies-literature | 2021 Apr

REPOSITORIES: biostudies-literature