氧和含巯基化合物对辐照转化DNA的影响。III. 反应速率。

Effects of oxygen and sulphydryl-containing compounds on irradiated transforming DNA. III. Reaction rates.

作者信息

Held K D, Harrop H A, Michael B D

出版信息

Int J Radiat Biol Relat Stud Phys Chem Med. 1984 Jun;45(6):627-36. doi: 10.1080/09553008414550891.

Abstract

The absolute rate for the repair reaction of radiation-induced, oxygen-dependent lesions in bacterial transforming DNA with the sulphydryl (SH)-containing compound dithiothreitol (DTT) has been determined using a fast response method, the gas explosion technique, to be 1.6 X 10(6) mol-1 s-1. Glutathione reacts ten times slower than DTT with the irradiated transforming DNA. It can also be calculated that transforming DNA radicals react with O2 in a damage-fixing reaction with a rate of about 3 X 10(8) dm3 mol-1 s-1. These rates are compared with values in the literature for reaction rates of SH, compounds and O2 with irradiated DNA constituents and with bacterial cells.

摘要

采用快速响应方法——气体爆炸技术，已测定出含巯基（SH）的化合物二硫苏糖醇（DTT）对细菌转化DNA中辐射诱导的氧依赖性损伤的修复反应绝对速率为1.6×10⁶ mol⁻¹ s⁻¹。谷胱甘肽与经辐照的转化DNA反应的速度比DTT慢十倍。还可以计算出，转化DNA自由基在损伤修复反应中与O₂反应的速率约为3×10⁸ dm³ mol⁻¹ s⁻¹。将这些速率与文献中关于SH化合物和O₂与经辐照的DNA成分及细菌细胞反应速率的值进行了比较。