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Mass spectrometric investigation of the sequence selectivity for adduction of heterocyclic aromatic amines on single‐strand oligonucleotides
Author(s) -
Jamin Emilien L.,
Arquier Delphine,
Tulliez Jacques,
Debrauwer Laurent
Publication year - 2008
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.3707
Subject(s) - chemistry , oligonucleotide , adduct , quinoline , electrospray ionization , context (archaeology) , guanine , nucleobase , sequence (biology) , mass spectrometry , pyridine , tandem mass spectrometry , dna , stereochemistry , chromatography , medicinal chemistry , organic chemistry , biochemistry , nucleotide , paleontology , gene , biology
Heterocyclic aromatic amines (HAAs) generated during the cooking of meats are known to be genotoxic substances able to form covalent bonds with DNA bases after metabolic activation. This work aimed at the investigation of the influence of the local environment of nucleobases along the nucleotidic sequence on its modification induced by two different HAAs, namely 2‐amino‐1‐methyl‐6‐phenylimidazo[4,5‐ b ]pyridine (PhIP) and 2‐amino‐3‐methylimidazo[4,5‐ f ]quinoline (IQ), in order to identify possible sequences more susceptible to modification. A systematic study of the neighbouring base effect on the adduction was emphasized. Thus, PhIP and IQ adducts have been synthesized with various T‐rich model single‐strand oligonucleotides displaying different flanking bases (A, G, C or T) at the 3′ or the 5′ side of the targeted guanine, which allowed a comparison of the flanking base effects on adduction. Modified oligonucleotides were then analyzed by high‐performance liquid chromatography (HPLC) coupled to electrospray ionization mass spectrometry. The localization of the modifications induced by PhIP or IQ along the oligonucleotide sequence was achieved by tandem mass spectrometry, and modification yields of the various model sequences were compared. Results indicate a favouring sequence context effect on the G‐C8‐IQ adduct formation with the sequence 5′ GGG 3′ . Although higher than IQ, modification yields observed with PhIP showed a less obvious effect of the neighbouring base on the G‐C8‐PhIP adduct formation, with a preferential sequence 5′ GGA/G/T 3′ . Copyright © 2008 John Wiley & Sons, Ltd.