Reactions of deoxyribonucleic acid radicals with sulfhydryl compounds in x-irradiated bacteriophase systems

Journal Article · Mon Apr 01 04:00:00 EST 1963 · Radiation Res.

DOI:https://doi.org/10.2307/3571401· OSTI ID:4717023

Howard-Flanders, P; Levin, J; Theriot, L

The effects of oxygen and nitric oxide on the inactivation of T2 phage by x rays were investigated both when the free phage was suspended in nutrient broth and when it had adsorbed to the host E. coli B. It was found that, when protected from indirect radiation effects by nutrient broth, the free phage is protected 1.8-fold by hydrogen sulfide and mercaptoethanol, but that this protection is reversed by oxygen or nitric oxide. At higher concentrations of sulfhydryl (20 to 200 mM), the protection is no longer fully reversed by the gases. Analysis of the results indicates that, as regards effect on x-rayinactivation, oxygen and the sulfhydryl are in competition. It is suggested that the substances compete for radioinduced phage DNA radicals, and that anoxic protection is the result of reaction between the sulfhydryl and the phage DNA in which the sulfhydryl donates a hydrogen atom. It appears that the sulfhydryls react about one-thirtieth as rapidly as oxygen with the DNA radicals. The results are discussed in terms of reaction mechanisms. (P.C.H.)

• Research Organization: Yale Univ., New Haven
• NSA Number: NSA-17-023186
• OSTI ID: 4717023
• Journal Information: Radiation Res., Journal Name: Radiation Res. Vol. Vol: 18
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
62 RADIOLOGY AND NUCLEAR MEDICINE
BACTERIA
BACTERIOPHAGES
BIOCHEMISTRY
DNA
ETHANOL
FREE RADICALS
HYDROGEN SULFIDES
NITROGEN OXIDES
NUCLEIC ACIDS
ORGANIC SULFUR COMPOUNDS
OXYGEN
QUANTITY RATIO
RADIATION EFFECTS
RADIATION PROTECTION
REACTION KINETICS
SULFHYDRYL RADICALS
SUSPENSIONS
VELOCITY
X RADIATION