Marta Blumenfeld

Synthesis and properties of DNA dumbbells containing chemically active substituted pyrophosphate internucleotide groups

Abstract DNA dumbbells with substituted pyrophosphate groups at a definite position of the sugar-phosphate backbone were synthesized by condensation of terminal 5′-phosphomonester- and 3′-methylphosphodiester groups in nicked dumbbells. N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide was used as a condensing agent. An efficient method for producing extended oligonucleotides carrying an O-methyl-substitued 3′-phosphate group was developed. Properties of the modified DNA-dumbbells were investigated. The substituted pyrophosphate group in the DNA dumbbells was efficiently cleaved under the action of N-methylimidazole or ethylendiamine aqueous solutions at pH 8.0.