Hindered rotation of the CH3 group in L-alanine single crystals: Temperature-induced transformation of the ESR spectrum

Abstract

Temperature-induced transformation of the ESR spectrum in γ-irradiated single crystals of the protein aminoacid L alanine, caused by hindered rotation of the CH3 group was studied. The rotation parameters as derived from the transformation of the ESR spectrum (activation energy U=0.18 eV, prefactor ω0=1×1013 s−1) are in satisfactory agreement with the values obtained earlier from measurements of the proton spin-lattice relaxation in polycrystalline alanine samples.