Characterization of DNA strand breakage in vitro by the antitumor protein neocarzinostatin.
Characterization of DNA strand breakage in vitro by the antitumor protein neocarzinostatin.
复制标题
抗肿瘤蛋白新制癌菌素体外 DNA 链断裂的表征。
DOI：
10.1021/bi00622a023
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发表时间：
1977
期刊：
影响因子：
2.9
通讯作者：
I. Goldberg
中科院分区：
文献类型：
--
作者：
R. Poon;T. Beerman;I. Goldberg
抗肿瘤蛋白质抗生素新抑癌素在巯基化合物存在下在体外引起DNA链断裂。断裂在本质上是单链的并且带有5 '-磷酰基末端。所有四种脱氧单核苷酸在切割位点的5 '端都是可恢复的，尽管始终发现较高比例的dGMP和TMP。开发了定量测定法以确定反应的pH曲线和时间过程。用合成和天然DNA进行的保护实验的数据表明，切割DNA需要胸苷酸和脱氧腺苷酸。在DNA-RNA杂交体中，核糖腺苷酸可以取代脱氧腺苷酸，而核糖尿苷酸不能取代胸苷酸。检测到胸腺嘧啶的释放，并且释放量与链断裂的数目良好相关。
The antitumor protein antibiotic neocarzinostatin causes strand scission of DNA in vitro in the presence of a sulfhydryl compound. The breaks are single stranded in nature and bear 5'-phosphoryl termini. All four deoxymononucleotides are recoverable at the 5'-ends of the cleavage sites although a higher proportion of dGMP and TMP are consistently found. The lesions are not repairable with polynucleotide ligase from Escherichia coli. A quantitative assay was developed to determine the pH profile and time course of the reaction. Data from protection experiments with synthetic and natural DNAs indicate the requirement for thymidylic acid and deoxyadenylic acid in the DNA for cutting. In DNA-RNA hybrids, riboadenylic acid can substitute for deoxyadenylic acid, whereas ribouridylic acid cannot substitute for thymidylic acid. Release of thymine is detected, and the amount of release correlates well with the number of strand scissions.