Investigating the Role of T<sub>7</sub> and T<sub>12</sub> Residues on the Biological Properties of Thrombin-Binding Aptamer: Enhancement of Anticoagulant Activity by a Single Nucleobase Modification
作者:Nicola Borbone、Mariarosaria Bucci、Giorgia Oliviero、Elena Morelli、Jussara Amato、Valentina D’Atri、Stefano D’Errico、Valentina Vellecco、Giuseppe Cirino、Gennaro Piccialli、Caterina Fattorusso、Michela Varra、Luciano Mayol、Marco Persico、Maria Scuotto
DOI:10.1021/jm301414f
日期:2012.12.13
that TBA-T7b is more potent than TBA in prolonging clotting time. On the other hand, in purified fibrinogen assay the thrombin inhibitory activity of both modified sequences was lower than that of TBA using human enzyme, whereas the potency trend was again reversed using bovine enzyme. Obtained structure–activity relationships were investigated by structural and computational studies. Taken together, these
合成了一个无环嘧啶类似物,它包含一个在嘧啶环上稠合的五元环,并被引入到15-聚寡脱氧核苷酸GGTTGGTGTGGGGGG的7位或12位,称为凝血酶结合适体(TBA)。表征1个所得适体的1 H NMR和CD光谱,TBA-T 7 b和TBA-T 12 b,显示了他们的折叠成由TBA形成的典型反平行chairlike G-四链体结构的能力。明显的CD熔融温度表明,主要在位置7处引入无环残基相对于TBA提高了所得G-四链体的热稳定性。然后在PT分析中评估了新分子的抗凝活性,结果表明TBA-T7 b是在延长凝血时间比TBA更有效。另一方面,在纯化的纤维蛋白原测定中,两种修饰序列的凝血酶抑制活性均低于使用人酶的TBA,而使用牛酶则再次逆转了效价趋势。通过结构和计算研究对获得的结构-活性关系进行了研究。综上所述,这些结果揭示了TBA残基T 7和T 12的活跃作用以及位于蛋白质的阴离子结合异位点I中的某些