A proposed mechanism for the mutagenicity of 5-formyluracil

被引：85

作者：

Privat, EJ ^{[1
]}

Sowers, LC ^{[1
]}

机构：

[1] CITY HOPE NATL MED CTR,DIV PEDIAT,DUARTE,CA 91010

来源：

MUTATION RESEARCH-FUNDAMENTAL AND MOLECULAR MECHANISMS OF MUTAGENESIS | 1996年 / 354卷 / 02期

关键词：

mutagenic mechanism; 5-formyluracil; oxidized base;

D O I：

10.1016/0027-5107(96)00005-X

中图分类号：

Q81 [生物工程学（生物技术）]; Q93 [微生物学];

学科分类号：

071005 ; 0836 ; 090102 ; 100705 ;

摘要：

5-Formyluracil is a mutagenic base formed in DNA by oxidation of the thymine methyl group. Whereas the thymine methyl group is electron donating, the formyl group is electron withdrawing, predicting increased ionization of the N-3 imino proton under physiological conditions. The pK(a) values of a series of 5-substituted uracil and deoxyuridine derivatives have been measured. A linear relationship is observed between the electronic inductive property of the 5-substituent and the pK(a) value of the corresponding imino proton. The pK(a) value of 5-formyl-2'-deoxyuridine is close to that of the mutagenic nucleoside analogue 5-bromo-2'-deoxyuridine. In analogy with BrU, it is proposed that the mutagenicity of 5-formyluracil results from enhanced mispairing of the ionized form with guanine during DNA replication.

引用

页码：151 / 156

页数：6

共 21 条

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