Department of Chemistry and Chemical Biology, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana 46202, USA.
J Org Chem. 2013 Apr 5;78(7):3021-9. doi: 10.1021/jo400013n. Epub 2013 Mar 26.
5-(α-Thyminyl)-5,6-dihydrothymine, also called spore photoproduct or SP, is commonly found in the genomic DNA of UV-irradiated bacterial endospores. Despite the fact that SP was discovered nearly 50 years ago, its biochemical impact is still largely unclear due to the difficulty of preparing SP-containing oligonucleotide in high purity. Here, we report the first synthesis of the phosphoramidite derivative of dinucleotide SP TpT, which enables successful incorporation of SP TpT into oligodeoxyribonucleotides with high efficiency via standard solid-phase synthesis. This result provides the scientific community a reliable means to prepare SP-containing oligonucleotides, laying the foundation for future SP biochemical studies. Thermal denaturation studies of the SP-containing oligonucleotide found that SP destabilizes the duplex by 10-20 kJ/mol, suggesting that its presence in the spore-genomic DNA may alter the DNA local conformation.
5-(α-胸腺嘧啶基)-5,6-二氢胸腺嘧啶，也称为孢子光产物或 SP，通常存在于经紫外线照射的细菌芽孢的基因组 DNA 中。尽管 SP 是近 50 年前发现的，但由于难以制备高纯度含 SP 的寡核苷酸，其生化影响在很大程度上仍不清楚。在这里，我们报告了二核苷酸 SP TpT 的亚磷酰胺衍生物的首次合成，这使得通过标准固相合成高效地将 SP TpT 掺入寡脱氧核糖核苷酸中成为可能。这一结果为科学界提供了一种可靠的方法来制备含 SP 的寡核苷酸，为未来的 SP 生化研究奠定了基础。对含 SP 的寡核苷酸的热变性研究发现，SP 通过 10-20 kJ/mol 使双链体不稳定，这表明其在芽孢基因组 DNA 中的存在可能会改变 DNA 的局部构象。
