Letsinger R L, Hapke B, Petersen G R, Dumas L B
Nucleic Acids Res. 1976 Apr;3(4):1053-63. doi: 10.1093/nar/3.4.1053.
Duplex circular phiX174 DNA (RF I) containing some phosphoramidate links in the backbone chain of the (-) strand was synthesized by reaction of 5'-amino-5'-deoxythymidine 5'-triphosphate, dCTP, dGTP, and 3H-dATP with DNA polymerase I and DNA ligase (T4) on a (+) strand phiX174 amber 3 DNA template. The yield of duplex DNA was higher when dTTP was included along with the amino analog in the initial reaction system or was added late in the synthesis. RF I DNA was observed as a rapidly sedimenting species in an alkaline sucrose gradient, and the presence of phosphoramidate linkages was demonstrated by the unusual lability of the duplex DNA in a weakly acidic solution.
通过在（+）链phiX174琥珀3 DNA模板上，使5'-氨基-5'-脱氧胸苷5'-三磷酸、dCTP、dGTP和3H-dATP与DNA聚合酶I和DNA连接酶（T4）反应，合成了在（-）链主链中含有一些氨基磷酸酯键的双链环状phiX174 DNA（RF I）。当在初始反应体系中与氨基类似物一起加入dTTP或在合成后期加入dTTP时，双链DNA的产量更高。在碱性蔗糖梯度中，RF I DNA表现为快速沉降的物质，并且双链DNA在弱酸性溶液中的异常不稳定性证明了氨基磷酸酯键的存在。
