Different rate-limiting steps in excision repair of ultraviolet- and N-acetoxy-2-acetylaminofluorene-damaged DNA in normal human fibroblasts.
Different rate-limiting steps in excision repair of ultraviolet- and N-acetoxy-2-acetylaminofluorene-damaged DNA in normal human fibroblasts.
复制标题
正常人成纤维细胞中紫外线和 N-乙酰氧基-2-乙酰氨基芴损伤的 DNA 切除修复的不同限速步骤。
DOI：
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复制
发表时间：
1977
影响因子：
11.1
通讯作者：
R. Setlow
中科院分区：
文献类型：
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作者：
F. Ahmed;R. Setlow
In normal human cells the amount of excision of ultraviolet damage to DNA saturates at high doses. In these cells some chemicals mimic ultraviolet damage as far as their biological and repair characteristics are concerned. One of these chemicals is N-acetoxy-2-acetylaminofluorene. We determined whether the limited repair capacity for ultraviolet damage was affected by treatment with N-acetoxy-2-acetylaminofluorene. To measure repair we determined unscheduled DNA synthesis and the number of sites sensitive to an ultraviolet endonuclease in an assay using an extract of Micrococcus luteus. The nuclease does not act on DNA treated with the chemical. The amount of unscheduled DNA synthesis due to a combined chemical and ultraviolet treatment was the sum of those observed from the separate treatments, even at saturation doses. The combined treatment did not affect the removal of nuclease-sensitive sites. We conclude that there are different rate-limiting steps in excision repair of the ultraviolet and the chemical damage and suggest a model involving a complex of enzymes to explain the data.
