Redoxactive Oligonucleotides: Synthesis and Properties of Flavocoenzyme-DNA

✍ Scribed by Alexandra Mees; Christoph Behrens; Anja Schwögler; Matthias Ober; Thomas Carell

• Publisher: John Wiley and Sons
• Year: 2003
• Tongue: English
• Weight: 269 KB
• Volume: 2003
• Category: Article
• ISSN: 1434-193X
• DOI: 10.1002/ejoc.200300066

✦ Synopsis

Abstract

The flavin heterocycle is the key component in the important and ubiquitous FMN and FAD coenzymes. As such, the flavin is able to catalyse oxygen‐transfer reactions in many monooxygenases, as well as one‐ and two‐electron transfer processes. We recently inserted the flavin heterocycle into oligonucleotides with the future goal of creating flavindependent ribozymes with redox‐catalytic properties. We showed that a flavin inside duplex DNA is able to exchange electrons with its environment. These electron‐exchange capabilities strongly modulate the fluorescence properties of the flavin heterocycle in DNA. Herein we report a detailed study of how DNA single and double strands change the fluorescence intensity of the flavin cofactor. In agreement with the assumption that the flavin photooxidises predominately guanine and adenine bases, we observe the strongest fluorescence quenching when the flavin is in close contact with one of these purine nucleobases. No fluorescence quenching is observed in the presence of pyrimidine bases. We conclude that A and G in a DNA environment have a similar effect as Trp and Tyr in a protein surrounding, regarding the fluorescence properties of the flavin coenzyme. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)