Premium
Silver‐Mediated Base Pairs in DNA Incorporating Purines, 7‐Deazapurines, and 8‐Aza‐7‐deazapurines: Impact of Reduced Nucleobase Binding Sites and an Altered Glycosylation Position
Author(s) -
Zhao Hang,
Leonard Peter,
Guo Xiurong,
Yang Haozhe,
Seela Frank
Publication year - 2017
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201605982
Subject(s) - nucleobase , glycosylation , purine metabolism , chemistry , dna , base pair , biochemistry , stereochemistry , enzyme
Formation of silver‐mediated DNA was studied with oligonucleotides incorporating 8‐aza‐7‐deazapurine, 7‐deazapurine, and purine nucleosides. The investigation was performed on non‐self‐complementary duplexes with one or two modifications and self‐complementary duplexes with an alternating dA–dT motif. Homo base pairs as well as base pair mismatches of dA analogues with dC and Watson–Crick pairs with dT were studied by stoichiometric silver ion titration and T m measurements. N 8 ‐Glycosylated 8‐aza‐7‐deazaadenine forms silver‐ion‐mediated base pairs capturing two silver ions (low silver content) whereas regularly glycosylated 8‐aza‐7‐deazapurine, 7‐deazapurine (c 7 A d ), and dA do not form comparable structures. Stable silver‐mediated “dA–dC” base pair mismatches were detected for all nucleosides. Two silver ions per base pair are bound by 8‐aza‐7‐deazapurine whereas c 7 A d binds only one silver ion. The situation is different when the equivalents of silver ions were increased to the number of total base pairs. Surprisingly, in 12‐mer duplexes as well as in related 25‐mer duplexes every base pair consumed one silver ion.