title: A study of side reactions occurring during synthesis of oligodeoxynucleotides containing O6-alkyldeoxyguanosine residues at preselected sites.
abstract: As part of our studies on the molecular mechanisms of mutation by carcinogens we have synthesized 12 oligonucleotides (15-mers) containing an O6-alkylguanine residue at a preselected position for use as primers in the enzymatic synthesis of biologically active DNA. Ten of these oligonucleotides are derived from a minus strand sequence carrying the modified nucleotide in the third codon of gene G of bacteriophage phi X174 DNA. Two others are derived from plus strand sequences carrying the modification in the 12th codon of the human Ha-ras protooncogene. During this work several potentially serious side reactions, which could complicate interpretation of mutagenesis data, were observed. This paper describes a detailed study of these reactions. Since we were unable to avoid undesirable side products, we developed simple chromatographic methods for detecting and removing them.
mesh_terms: D000478:Alkylation; D001483:Base Sequence; D003849:Deoxyguanosine / Q000031:analogs & derivatives*; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D009838:Oligodeoxyribonucleotides / Q000138:chemical synthesis*
chemical_list: D007202:Indicators and Reagents; D009838:Oligodeoxyribonucleotides; D003849:Deoxyguanosine