Formation of 5-formyl-2'-deoxycytidine from 5-methyl-2'-deoxycytidine in duplex DNA by Fenton-type reactions and gamma-irradiation.
Nucleic Acids Res
; 27(22): 4385-90, 1999 Nov 15.
Article
en En
| MEDLINE
| ID: mdl-10536146
ABSTRACT
5-methyl-2'-deoxycytidine (5-Me-dC) is formed by the enzymatic methylation of dC, primarily in CpG sequences in DNA, and is involved in the regulation of gene expression. In the present study, 5-Me-dC and double-stranded DNA fragments containing 5-Me-dC were either gamma-irradiated or aerobically treated with Fenton-type reagents, Fe(II)-EDTA, Fe(II)-nitrilotriacetic acid, Fe(III)-EDTA-H(2)O(2)-catechol or ascorbic acid-H(2)O(2) under neutral conditions. The formation of 5-formyl-2'-deoxycytidine (5-CHO-dC) was observed upon treatment of both 5-Me-dC and DNA fragments containing 5-Me-dC. The yields of 5-CHO-dC from 5-Me-dC and those of 5-formyl-2'-deoxyuridine from dT were comparable. These results suggest that 5-Me-dC in DNA is as susceptible to oxidation as dT in cells, and raise the possibility that 5-CHO-dC may contribute to the high mutagenic rate observed in CpG sequences in genomic DNA.
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
ADN
/
Desoxicitidina
/
Rayos gamma
/
Peróxido de Hidrógeno
/
Hierro
Idioma:
En
Año:
1999
Tipo del documento:
Article