muramidase and tert-nitrosobutane

Free radicals produced by gamma-irradiation of solid lysozyme were investigated by a technique combining ESR, spin-trapping and enzymatic digestion. MNP and DMPO were used as spin-trapping reagents. The solid lysozyme was first gamma-irradiated and then dissolved in an aqueous solution containing the spin-trapping reagent to stabilize free radicals. The spin adducts of lysozyme were digested to oligopeptides to get ESR spectra having a well-resolved hyperfine structure. The ESR spectra obtained showed that carbon-centered radicals, -CH-, at the side chains of amino acids, and thiyl radicals, -CH2-S., at disulfide bridges were produced in gamma-irradiated solid lysozyme.

Topics: Electron Spin Resonance Spectroscopy; Free Radicals; Gamma Rays; Muramidase; Nitroso Compounds; Spin Labels