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Influence of the Absolute Configuration of NPE‐Caged Cytosine on DNA Single Base Pair Stability
Author(s) -
Steinert Hannah S.,
Schäfer Florian,
Jonker Hendrik R. A.,
Heckel Alexander,
Schwalbe Harald
Publication year - 2014
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201307852
Subject(s) - chemistry , base pair , duplex (building) , cytosine , dna , base (topology) , proton nmr , nuclear magnetic resonance spectroscopy , stereochemistry , absolute configuration , crystallography , biochemistry , mathematical analysis , mathematics
Photolabile protecting groups are a versatile tool to trigger reactions by light irradiation. In this study, we have investigated the influence of the absolute configuration of the 1‐(2‐nitrophenyl)ethyl (NPE) cage group on a 15‐base‐pair duplex DNA. Using UV melting, we determined the global stability of the unmodified and the selectively ( S )‐ and ( R )‐NPE‐modified DNA sequences, respectively. We observe a differently destabilizing effect for the two NPE stereoisomers on the global stability. Analysis of the temperature dependence of imino proton exchange rates measured by NMR spectroscopy reveals that this effect can be attributed to decreased base pair stabilities of the caged and the 3′‐neighbouring base pair, respectively. Furthermore, our NMR based structural models of the modified duplexes provide a structural basis for the distinct effect of the ( S )‐ and the ( R )‐NPE group.