单线态分子氧导致大肠杆菌中质粒DNA（pBR322）转化活性丧失。

Loss of transforming activity of plasmid DNA (pBR322) in E. coli caused by singlet molecular oxygen.

作者信息

Wefers H, Schulte-Frohlinde D, Sies H

出版信息

FEBS Lett. 1987 Jan 19;211(1):49-52. doi: 10.1016/0014-5793(87)81272-3.

Abstract

Plasmid DNA pBR322 in aqueous solution was exposed to singlet molecular oxygen (1O2) generated by microwave discharge. DNA damage was detected as loss of transforming activity of pBR322 in E. coli (CMK) dependent on the time of exposure. DNA damage was effectively decreased by singlet-oxygen quenchers such as sodium azide and methionine. Replacement of water in the incubation buffer by D2O led to an increase in DNA damage. 9,10-Bis(2-ethylene)anthracene disulfate was used as a chemical trap for 1O2 quantitation by HPLC analysis of the endoperoxide formed.

摘要

将水溶液中的质粒DNA pBR322暴露于微波放电产生的单重态分子氧（1O2）中。检测到pBR322在大肠杆菌（CMK）中的转化活性丧失，以此作为DNA损伤的指标，该损伤取决于暴露时间。叠氮化钠和蛋氨酸等单重态氧猝灭剂可有效降低DNA损伤。用重水（D2O）替代孵育缓冲液中的水会导致DNA损伤增加。使用9,10-双（2-乙烯基）蒽二硫酸盐作为化学捕集剂，通过对形成的内过氧化物进行高效液相色谱分析来定量1O2。