Visscher J, Schwartz A W
Evolutionary Biology Research Group, Faculty of Science, University of Nijmegen, The Netherlands.
Nucleic Acids Res. 1992 Nov 11;20(21):5749-52. doi: 10.1093/nar/20.21.5749.
Pyrophosphate linkages have a number of important roles in biology and are also formed chemically with great ease. They often are unwanted products, such as in the nonenzymatic oligomerization of mononucleotides. We have found that Zr(4+)- and Th(4+)-ions catalyze the symmetrical hydrolysis of pyrophosphate linkages. Oligonucleotide analogs linked by pyrophosphate bonds are substantially degraded in the presence of these metals, even at 0 degrees C. Conditions are described which permit the decapping of a pyrophosphate capped oligonucleotide. Oligodeoxynucleotides can be decapped by this procedure without cleavage of phosphodiester linkages. Oligoribonucleotides are susceptible to partial hydrolysis and require purification by HPLC after decapping.
焦磷酸键在生物学中具有许多重要作用，并且在化学上也很容易形成。它们常常是不需要的产物，例如在单核苷酸的非酶促寡聚化过程中。我们发现Zr(4+)和Th(4+)离子催化焦磷酸键的对称水解。即使在0摄氏度，由焦磷酸键连接的寡核苷酸类似物在这些金属存在下也会大量降解。文中描述了允许对焦磷酸封端的寡核苷酸进行去封端的条件。通过此程序可以使寡脱氧核苷酸去封端而不裂解磷酸二酯键。寡核糖核苷酸易发生部分水解，去封端后需要通过高效液相色谱法进行纯化。
