Nucleic Acid Labeling, Ligation, and Modification
El-Sagheer AH., Brown T.
In recent years the CuI-catalyzed [3+2] azide-alkyne cycloaddition (CuAAC) and strain-promoted azide-alkyne [3+2] cycloaddition (SPAAC) reactions have been used to great effect in the nucleic acid field for DNA and RNA labeling, strand ligation, and the generation of artificial nucleic acid backbones. This chapter focuses on the most recent examples of DNA and RNA functionalization and ligation in which the CuAAC and SPAAC reactions have been applied. Chemical ligation of DNA and RNA strands has certain advantages over enzymatic ligation; it can be carried out on a large scale, and it is compatible with a wide range of chemical modifications in the DNA strands as well as being compatible with nucleic acid analogs. To achieve chemical ligation, alkyne- and azide-labeled DNA strands can be joined together efficiently by the CuAAC reaction to give an artificial triazole backbone at the point of ligation.