Independent generation and characterization of a C2'-oxidized abasic site in chemically synthesized oligonucleotides.
Abasic lesions, which are formed endogenously and as a consequence of exogenous agents, are lethal and mutagenic. Hydrogen atom abstraction from C2' in DNA under aerobic conditions produces an oxidized abasic lesion (C2-AP), along with other forms of DNA damage. The effects of C2-AP on DNA structure and function are not well understood. A method for the solid-phase synthesis of oligonucleotides containing C2-AP lesions is reported. The lesion is released via periodate oxidation of a triol containing a vicinal diol. The triol is introduced via a phosphoramidite that is compatible with standard oligonucleotide synthesis and deprotection conditions. UV-melting studies indicate that the C2-AP lesion has a comparable effect on the thermal stability of duplex DNA as other abasic lesions. The C2-AP lesion is rapidly cleaved by piperidine at 90 degrees C. However, cleavage by NaOH (0.1 M, 37 degrees C) shows that C2-AP is considerably less labile (t(1/2) = 3.3 +/- 0.2 h) than other abasic lesions.
Kim
Jaeseung
J
Department of Chemistry, Johns Hopkins University, 3400 N. Charles St., Baltimore, Maryland 21218, USA.
Weledji
Yvonne N
YN
Greenberg
Marc M
MM
D001483:Base Sequence; D004247:DNA / Q000737:chemistry*; D004249:DNA Damage; D008958:Models, Molecular; D015394:Molecular Structure; D009841:Oligonucleotides / Q000138:chemical synthesis*; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D010880:Piperidines / Q000737:chemistry; D013997:Time Factors
D009841:Oligonucleotides; D010880:Piperidines; D004247:DNA