Ionizing radiation and tritium transmutation both cause formation of 5-hydroxymethyl-2'-deoxyuridine in cellular DNA.
Ionizing radiation and tritium transmutation both cause formation of 5-hydroxymethyl-2'-deoxyuridine in cellular DNA.
复制标题
电离辐射和氚嬗变都会导致细胞 DNA 中 5-羟甲基-2-脱氧尿苷的形成。
DOI：
10.1073/pnas.81.2.318
复制
发表时间：
1984
影响因子：
11.1
通讯作者：
Goldstein,MS
中科院分区：
文献类型：
--
作者：
Teebor,GW;Frenkel,K;Goldstein,MS
在[甲基- 3h]胸苷存在下生长的HeLa细胞在其DNA中含有大量的5-羟甲基-2'-脱氧尿嘧啶（HMdU）。当细胞在[6-3H]胸苷中生长并将其DNA标记为相同的特异性活性时，不存在HMdU。当这些[6-3H]胸腺嘧啶标记的细胞暴露于越来越多的伽马辐射中时，它们的DNA中形成了少量但不断增加的HMdU。这表明HMdU可以通过两种不同的机制在DNA中形成。第一种是胸腺嘧啶甲基中3H转化为3He （β衰变）的结果，导致碳正离子的形成。这种寿命短的离子与水中的氢氧根离子反应，生成羟基。通过这种机制形成的HMdU以3H的衰变速率形成。它只出现在[甲基3h]胸苷残基中，存在于未辐照和γ辐照细胞的DNA中。第二种机制是电离辐射引起水的辐射分解的结果。所产生的自由基种类，特别是羟基自由基，可以与DNA上的许多位点发生反应。当胸腺嘧啶的甲基受到羟基自由基的攻击时，形成羟基甲基。只有当使用[6-3H]胸腺嘧啶标记的细胞时，才能检测到这种机制形成的HMdU，因为胸腺嘧啶6位3H的嬗变不能产生HMdU。
HeLa cells grown in the presence of [methyl-3H]thymidine contained large amounts of 5-hydroxymethyl-2'-deoxyuridine (HMdU) in their DNA. When the cells were grown in [6-3H]thymidine and their DNA was labeled to the same specific activity, no HMdU was present. When such [6-3H]thymidine-labeled cells were exposed to increasing amounts of gamma-radiation, small but increasing amounts of HMdU were formed in their DNA. This indicates that HMdU can be formed in DNA by two distinct mechanisms. The first is the result of the transmutation of 3H to 3He (beta decay) in the methyl group of thymidine, leading to formation of a carbocation. This short-lived ion reacts with hydroxide ions of water, yielding the hydroxymethyl group. HMdU that is formed by this mechanism is formed at the rate of beta decay of 3H. It appears only in [methyl-3H]thymidine residues and is present in the DNA of both nonirradiated and gamma-irradiated cells. The second mechanism is the result of the radiolysis of water caused by ionizing radiation. The resultant radical species, particularly hydroxyl radicals, may react with many sites on DNA. When the methyl group of thymine is attacked by hydroxyl radicals, the hydroxymethyl group is formed. The formation of HMdU by this mechanism was detected only when [6-3H]thymidine-labeled cells were used, since transmutation of 3H in position 6 of thymine cannot yield HMdU.
DNA 中辐射诱导的胸腺嘧啶衍生物的鉴定。
DOI：
10.1016/0065-2571(82)90007-3
发表时间：
1982
期刊：
Advances in enzyme regulation
影响因子：
--
作者：
Teebor,GW;Frenkel,K;Goldstein,MS
通讯作者：
Goldstein,MS