Held K D, Powers E L
Int J Radiat Biol Relat Stud Phys Chem Med. 1979 Dec;36(6):613-9. doi: 10.1080/09553007914551441.
The X-ray-induced inactivation of the biological activity of Bacillus subtilis transforming DNA in dilute aqueous solution has been studied over a wide range of O2 concentrations in an attempt to elucidate the mechanisms involved in O2 action. When the DNA is irradiated in the presence of 100 per cent O2 there is a protection of the transforming DNA compared to the sensitivity in N2-saturated or in N2O-saturated solutions. When the equilibrating gas contains intermediate concentrations of O2 (1 per cent--90 per cent) in N2 or N2O, the DNA sensitivity is equivalent to that in pure N2 or N2O respectively. At low O2 concentrations (approximately 0.14 per cent O2 in N2 or in N2O) there is a sensitization of the DNA and this sensitization can be prevented by .OH scavengers. Possible mechanisms for these actions of O2 on the radiation sensitivity of transforming DNA are discussed.
为了阐明氧气作用所涉及的机制，在很宽的氧气浓度范围内研究了X射线诱导的枯草芽孢杆菌转化DNA在稀水溶液中的生物活性失活情况。当DNA在100%氧气存在下进行辐照时，与在氮气饱和或一氧化二氮饱和溶液中的敏感性相比，转化DNA受到了保护。当平衡气体在氮气或一氧化二氮中含有中等浓度的氧气（1% - 90%）时，DNA敏感性分别与在纯氮气或纯一氧化二氮中的情况相当。在低氧气浓度下（氮气或一氧化二氮中约含0.14%氧气），DNA会出现敏化现象，且这种敏化作用可被羟基清除剂阻止。文中讨论了氧气对转化DNA辐射敏感性产生这些作用的可能机制。
