Electron Spin Resonance of Free Radicals in Irradiated Biochemicals

Abstract

Applications or paramagnetic resonance for the study of radiation effects are reviewed. The feature which makes electron magnetic resonance a natural method for the study of radiation damage to solids, or of free radicals within solids, is the fact that the method does not detect electrons of ordinary matter which have their magnetism canceled by pairing but detects only electrons knocked apart, as unpaired, by ionizing radiations or other means. The electron spin resonance patterns produced by x irradiation was determined for some twenty- five amino acids and a comparable number of di- or tripeptides and a large number of proteins. This survey showed that the electron spin resonance method is almost universally applicable to the study of biochemicals in the solid state. Results are reported from applications of electron spin resonance to studies on proteins and their constitutents, biological tissue treated with cysteine, cell components, human hemoglobin, thyroid and parathyroid extracts, steroids, and nucleic acids and their constituents. The effect of oxygen on the paramagnetic resonance signals of different types of irradiated biochemicals was also investigated. 22 references. (C.H.)