氧嗪在 DNA 链上对 T4 多核苷酸激酶、T4 DNA 连接酶和限制酶的生物分子反应。

Biomolecular response of oxanine in DNA strands to T4 polynucleotide kinase, T4 DNA ligase, and restriction enzymes.

机构信息

Department of Biotechnology and Bioinformatics, Korea University, Jochiwon, Chungnam 339-800, Republic of Korea.

出版信息

Biochem Biophys Res Commun. 2010 Jan 1;391(1):118-22. doi: 10.1016/j.bbrc.2009.11.013. Epub 2009 Nov 11.

DOI:10.1016/j.bbrc.2009.11.013

PMID:19900415

Abstract

Oxanine (Oxa), generated from guanine (Gua) by NO- or HNO(2)-induced nitrosative oxidation, has been thought to cause mutagenic problems in cellular systems. In this study, the response of Oxa to different enzymatic functions was explored to understand how similarly it can participate in biomolecular reactions compared to the natural base, Gua. The phosphorylation efficiency of the T4 polynucleotide kinase was highest when Oxa was located on the 5'-end of single stranded DNAs compared to when other nucleobases were in this position. The order of phosphorylation efficiency was as follows; Oxa>Gua>adenine (Ade) approximately thymine (Thy)>cytosine (Cyt). Base-pairing of Oxa and Cyt (Oxa:Cyt) between the ligation fragment and template was found to influence the ligation performance of the T4 DNA ligase to a lesser degree compared to Gua:Cyt. In addition, EcoRI and BglII showed higher cleavage activities on DNA substrates containing Oxa:Cyt than those containing Gua:Cyt, while BamHI, HindIII and EcoRV showed lower cleavage activity; however, this decrease in activity was relatively small.

摘要

氧嗪（Oxa）是由 NO 或 HNO2 诱导的硝化氧化作用从鸟嘌呤（Gua）生成的，被认为会在细胞系统中引起诱变问题。在这项研究中，我们探索了 Oxa 对不同酶功能的反应，以了解它与天然碱基 Gua 相比，如何参与生物分子反应。与其他核碱基位于这个位置相比，T4 多核苷酸激酶的磷酸化效率在单链 DNA 的 5'-末端存在 Oxa 时最高。磷酸化效率的顺序如下：Oxa>Gua>腺嘌呤（Ade）≈胸腺嘧啶（Thy）>胞嘧啶（Cyt）。我们发现，与 Gua:Cyt 相比，连接片段和模板之间的 Oxa:Cyt 碱基配对对 T4 DNA 连接酶的连接性能的影响较小。此外，EcoRI 和 BglII 对含有 Oxa:Cyt 的 DNA 底物的切割活性高于含有 Gua:Cyt 的 DNA 底物，而 BamHI、HindIII 和 EcoRV 的切割活性较低；然而，这种活性下降相对较小。