Hoogsteen-Duplex DNA: Synthesis and base pairing of oligonucleotides containing 1-deaza-2′-deoxyadenosine

✍ Scribed by Frank Seela; Thomas Wenzel

• Book ID: 102858651
• Publisher: John Wiley and Sons
• Year: 1994
• Tongue: German
• Weight: 859 KB
• Volume: 77
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.19940770604

✦ Synopsis

Oligodeoxyribonucleotides containing 1 -deaza-2'-deoxyadenosine ( = 7-amino-3-(2-deoxy#? -D-erythro -pentofuranosyl)-3H-imidazo[4,5-b]pyridine; lb) form Hoogsteen duplexes. Warson-Crick base pairs cannot be built up due to the absence of N(1). For these studies, oligonucleotide building blocksthe phosphonate 3a and the phosphoramidite 3b -were prepared from l b via 4a and 5, as well as the Fractosil-linked 6b, and used in solid-phase synthesis. The applicability of various N-protecting groups (see 4a-c) was also studied. The Hoogsfeen duplex d[(c1A),,]~d(T2,,) (11'13; T,,, 15") is less stable than d(A2,).d(T2,) (12.13; T, 60"). The block oligomers ~[(C~A)~,-T,,] (14) and d[TIo-(c'A),,] (15) containing purine and pyrimidine bases in the same strand are also able to form duplexes with each other. The chain polarity was found to be parallel.