A non-enzymatic method is provided for binding a first nucleic acid chain to a second nucleic acid chain without introducing a sulfur atom into the combined nucleic acid chain, the method comprising reacting a first nucleic acid chain having a phosphorothioate group at the 3′ or 5′ terminus with a second nucleic acid chain having a hydroxyl group or an amino group at the 3′ or 5′ terminus in the presence of an electrophile that has a leaving group and is configured to leave the leaving group and bind to a sulfur atom of the phosphorothioate group of the first nucleic acid chain at the site to which the leaving group had been bound, and remove the sulfur atom from the phosphorothioate group of the first nucleic acid chain and a hydrogen atom from the hydroxyl group or from the amino group of the second nucleic acid chain via a nucleophilic substitution with an oxygen atom of the hydroxyl group or a nitrogen atom of the amino group of the second nucleic acid chain, and thereby form a bond between a phosphorus atom of the phosphate group of the first nucleic acid chain and the oxygen atom or the nitrogen atom of the second nucleic acid chain. Examples of structures produced by the binding method are shown below.
本发明提供了一种非酶促方法,用于将第一核酸链与第二核酸链结合而不在结合的核酸链中引入
硫原子、该方法包括使第一核酸链与第二核酸链反应,第一核酸链的 3′或 5′末端具有
硫代磷酸酯基团,第二核酸链的 3′或 5′末端具有羟基或
氨基。具有离去基团的亲电子体,该亲电子体配置成离开离去基团,并在离去基团结合的部位与第一核酸链的
硫代磷酸酯基团的
硫原子结合、并通过与第二核酸链的羟基的氧原子或
氨基的氮原子的亲核取代作用,从第一核酸链的
硫代磷酸酯基团中除去
硫原子,并从第二核酸链的羟基或
氨基中除去氢原子,从而在第一核酸链的
磷酸基团的
磷原子与第二核酸链的氧原子或氮原子之间形成键。下面举例说明该结合方法产生的结构。