ELECTRON SPIN RESONANCE STUDIES ON THE MECHANISM OF ENZYME INACTIVATION BY DIRECT ACTION OF GAMMA RADIATION
Electron spin resonance spectra of a sulfhydryl enzyme urease, and a non- sulfhydryl enzyme, bacterial proteinase were observed after exposure to irradiation of gamma rays. Urease showed a characteristic pattern to a sulfhydryl protein and bacterial proteinase to a non-sulfhydryl protein. A quantitative relationship among inactivation of the proteinase, intensity of ESR signal of the enzyme, and irradiation dose of gamma rays, was measured. Whereas in an early process of the inactivation any significant increase of the intensity of ESR pattern was not observed, a paralle relationship between the inactivation of the enzyme and the increase of free radicals was found in a range from 100 kiloroentgen dose to 10 megaroentgen dose of gamma rays and no significant increase of the free radicals was found contrary to further progress of the inactivation of the enzyme in the course of the irradiation of larger doses than 10 megaroentgens. Possibility of conduction of electron vacancy from a damaged area of the enzyme molecule to an active center on the enzyme, and an inactivating mechanism by direct action of gamma radiation, were proposed and discussed. (auth)
- Research Organization:
- Kyoto Univ.
- NSA Number:
- NSA-17-027430
- OSTI ID:
- 4696609
- Journal Information:
- Bulletin of the Institute for Chemical Research, Kyoto University (Japan), Journal Name: Bulletin of the Institute for Chemical Research, Kyoto University (Japan) Vol. Vol: 41; ISSN BICRA
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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