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THE EFFECT OF 1,4‐DIAZABICYCLO[2.2.2]OCTANE ON THE RADIOSENSITIVITY OF BACTERIA
Author(s) -
Anderson Robert F.,
Patel Kantilal B.
Publication year - 1978
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.1978.tb07036.x
Subject(s) - dabco , chemistry , octane , radical , escherichia coli , bacteria , photochemistry , oxygen , peroxide , singlet oxygen , quenching (fluorescence) , biochemistry , organic chemistry , biology , genetics , physics , quantum mechanics , fluorescence , gene
— Hydroxyl radicals ('OH) are scavenged by 1,4‐diazabicyclo[2.2.2]octane (DABCO) at a diffusion‐controlled rate of 1.25 ± 0.1 × 10 9 M ‐1 s ‐1 . Unlike other efficient 'OH scavengers which exhibit protection of bacteria against irradiation both in oxic and hypoxic conditions, DABCO has been shown to protect Serratia marcescens and various strains of Escherichia coli only in oxic conditions. DABCO appears to eliminate a component of the sensitization afforded by oxygen in all strains of E. coli tested. The level of this protection increases from ∼15% in the wild type AB 1157 to ∼100% in the recA uvrA mutant AB 2480. It is suggested that DABCO protects against lethal events that can occur on macromolecules other than DNA such as the cell membrane. Results with added glycerol, as well as work in D 2 O solution, indicate that DABCO is more likely to be acting by scavenging radicals rather than by quenching 1 O 2 . If 1 O 2 is a component of the sensitization afforded by oxygen, then it is unlikely to be formed in a hydrophilic environment in the cell.