Improved synthesis of N1-substituted orotic acid derivatives
作者:Nicholas A. Senger、Jeannette T. Bowler、Rene S. Mercado、Sidney Lin、Weiming Wu
DOI:10.1016/j.tetlet.2013.05.136
日期:2013.8
An improvedmethod for the synthesis of N1-substituted oroticacid derivatives is reported. The method involves sequential incorporation of nitrogen atoms to the pyrimidine structure from simple starting materials and thus allows the synthesis of N1-substituted oroticacid derivatives with single 15N label at either N-1 or N-3.
Structural changes of an abasic site in duplex DNA affect noncovalent binding of the spin label ç
作者:Sandip A. Shelke、Snorri Th. Sigurdsson
DOI:10.1093/nar/gkr1210
日期:2012.4
The influence of structural changes of an abasic site in duplex DNA on noncovalent and site-directedspinlabeling (NC-SDSL) of the spinlabel ç were examined with electron paramagnetic resonance (EPR) spectroscopy. The binding affinities of ç to sixteen different DNA duplexes containing all possible sequences immediately flanking the abasic site were determined and the results showed that the binding
在双链DNA上的自旋标记的非共价和位点定向自旋标记(NC-SDSL)脱碱基位点的结构变化的影响ç与检查电子顺磁共振(EPR)波谱法。测定了ç与 16 个不同 DNA 双链体的结合亲和力,该双链体包含紧邻无碱基位点的所有可能序列,结果表明ç的结合高度依赖于侧翼序列。通常,5'-dG 核苷酸有利于自旋标记的结合。特别是,5'-d(G__T) 是最好的结合序列,而 5'-d(C__T) 表现出最低的亲和力。将无碱基位点接头的结构从四氢呋喃类似物 ( F ) 更改为核苷酸C3 -间隔( C 3)不会明显影响ç与无碱基位点的结合。为了有效结合ç,无碱基位点需要位于距离双链末端至少四个碱基对的位置。在ç 的N3 处引入甲基取代基不会改变结合亲和力,但观察到 N3-乙基和-丙基的结合降低。这些结果将指导核酸 NC-SDSL 的无碱基位点受体和自旋标记配体的设计。