Hartman P S, Eisenstark A, Pauw P G
Proc Natl Acad Sci U S A. 1979 Jul;76(7):3228-32. doi: 10.1073/pnas.76.7.3228.
A nonlethal concentration of H2O2 (0.05%) greatly enhances near-ultraviolet (NUV) inactivation of phage T7. Simultaneous treatment with H2O2 and NUV reduces the amount of DNA injected into the bacterial host, but not the number of phage adsorbed. Not only were recombination and gene expression of late markers reduced upon treatment of phage T7 with NUV plus H2O2, but also a gradient of recombination resulted, with markers injected first reduced to a lesser extent than those injected last. Double-strand DNA breaks were not detected; however, DNA-protein crosslinks were observed upon NUV plus H2O2 treatment of double-labeled T7. Previous studies demonstrated that single-strand DNA breaks did not account for phage death by NUV plus H2O2. It is concluded that the DNA-protein crosslinks prevent normal injection of T7 phage DNA; such crosslinks may be important lesions in NUV cellular damage.
非致死浓度的过氧化氢（0.05%）能极大地增强噬菌体T7的近紫外线（NUV）灭活作用。过氧化氢与近紫外线同时处理会减少注入细菌宿主的DNA量，但不会减少吸附的噬菌体数量。用近紫外线加过氧化氢处理噬菌体T7后，不仅晚期标记物的重组和基因表达减少，而且还产生了重组梯度，首先注入的标记物减少程度小于最后注入的标记物。未检测到双链DNA断裂；然而，在用近紫外线加过氧化氢处理双标记T7后观察到了DNA-蛋白质交联。先前的研究表明，单链DNA断裂不能解释近紫外线加过氧化氢导致的噬菌体死亡。得出的结论是，DNA-蛋白质交联会阻止T7噬菌体DNA的正常注入；这种交联可能是近紫外线细胞损伤中的重要损伤。
