[Chemical reactions in double-helical nucleic acids. XIV. Effectiveness of forming phosphodiester bonds between various nucleotide units].

Efficiency of the template-directed condensation of oligonucleotides depends on the nature of the nucleotide units to be joined. Fourteen out of sixteen dinucleotide combinations in double-stranded DNA were examined. Alterations of the reaction efficiency are identical for cyanogen bromide and 1-ethyl-3-(3'-dimethylaminopropyl)carbodiimide coupling reagents. Dependence of the chemical ligation efficiency on the DNA sequence-specific local conformation is discussed.