Formation of 5-formyl-2'-deoxycytidine from 5-methyl-2'-deoxycytidine in duplex DNA by Fenton-type reactions and gamma-irradiation.
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.
Murata-Kamiya
N
N
Department of Health Policy and Management, Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health, Kitakyushu, Japan.
Kamiya
H
H
Karino
N
N
Ueno
Y
Y
Kaji
H
H
Matsuda
A
A
Kasai
H
H
D001205:Ascorbic Acid / Q000737:chemistry; D002396:Catechols / Q000737:chemistry; D018899:CpG Islands / Q000528:radiation effects; D004247:DNA / Q000737:chemistry* / Q000528:radiation effects; D003841:Deoxycytidine / Q000031:analogs & derivatives* / Q000737:chemistry; D003853:Deoxyribonucleosides / Q000737:chemistry / Q000528:radiation effects; D004492:Edetic Acid / Q000737:chemistry; D005290:Ferric Compounds / Q000737:chemistry; D005296:Ferrous Compounds / Q000737:chemistry; D005720:Gamma Rays; D006861:Hydrogen Peroxide / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D010084:Oxidation-Reduction
C402104:5-formyl-2'-deoxycytidine; D002396:Catechols; D003853:Deoxyribonucleosides; C045076:Fenton's reagent; D005290:Ferric Compounds; D005296:Ferrous Compounds; D003841:Deoxycytidine; C055526:Fe(II)-EDTA; D004247:DNA; D004492:Edetic Acid; C016569:5-methyldeoxycytidine; D006861:Hydrogen Peroxide; D007501:Iron; C019179:Fe(III)-EDTA; C034221:catechol; D001205:Ascorbic Acid