CHEMICAL MODIFICATION OF RADIATION TOXICITY VIA THE COPPER COMPONENT OF CYTOCHROME c OXIDASE. I. OUTLINE OF THEORY
Technical Report
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OSTI ID:4818971
It is proposed that the primary cytoplasmic action of ionizing radiation is to promote the oxidation of the cuprous Cu component of cyiochrome c oxidase. Copper is a functional component of cytochrome oxidase and is localized at the terrninal position of the cytochrome respiratory chain. An acutely lethal dose of radiation is postulated to cause the irreversible oxidation of Cu(I) of cytochrome oxidase producing a cytoplasmic biochemical lesion. This results in the inactivation of the electron transport system involving the pacemaker enzyme, which is considered to be an analog of oxygen-carrying chelates in which Cu forms chargetransforming complexes with molecular oxygen. The cytoplasm lesion is assumed to contribute to the radiation damage suffered by the cell nucleus. It is pointed out that the most effective chemical protective agents against radiation toxicity are compounds that form complexes or chelates specifically with cuprous Cu, while chemical sensitizing agents are often complex-forming compounds specific for cupric Cu. Thus chemical protection is postulated to involve stabilization of Cu(I) and sensitization to involve stabilization of Cu(II) of cytochrome oxidase. Reaction mechanisms involved in both direct and indirect radiation protection and sensitization are discussed from the standpoint of the basic assumptions of the Cu(I)-Cu(II) theory. (C.H.)
- Research Organization:
- Argonne National Lab., Ill.
- NSA Number:
- NSA-16-025174
- OSTI ID:
- 4818971
- Report Number(s):
- TID-11988; UAC-4719
- Country of Publication:
- United States
- Language:
- English
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Journal Article
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Sun Sep 29 20:00:00 EDT 2019
· Proceedings of the National Academy of Sciences of the United States of America
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OSTI ID:1567869