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An Isosteric and Fluorescent DNA Base Pair Consisting of 4‐aminophthalimide and 2,4‐diaminopyrimidine as C‐Nucleosides
Author(s) -
Merkel Marcus,
Dehmel Lars,
Ernsting Nikolaus P.,
Wagenknecht HansAchim
Publication year - 2017
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.201608712
Subject(s) - chemistry , fluorescence , moiety , base pair , dna , stereochemistry , nuclear magnetic resonance spectroscopy , biochemistry , physics , quantum mechanics
A 13mer DNA duplex containing the artificial 4‐aminophthalimide:2,4‐diaminopyrimidine (4AP:DAP) base pair in the central position was characterized by optical and NMR spectroscopy. The fluorescence of 4AP in the duplex has a large Stokes shift of Δ λ =124 nm and a quantum yield of Φ F =24 %. The NMR structure shows that two interstrand hydrogen bonds are formed and confirms the artificial base pairing. In contrast, the 4‐ N , N ‐dimethylaminophthalimide moiety prefers the syn conformation in DNA. The fluorescence intensity of this chromophore in DNA is very low and the NMR structure shows no significant interaction with DAP. Primer‐extension experiments with DNA polymerases showed that not only is the 4AP C nucleotide incorporated at the desired position opposite DAP in the template, but also that the polymerase is able to progress past this position to give the full‐length product. The observed selectivity supports the NMR results.