Formation of the 1,N2-Glyoxal Adduct of Deoxyguanosine by Phosphoglycolaldehyde, a Product of 3‘-Deoxyribose Oxidation in DNA
作者:Mohamad Awada、Peter C. Dedon
DOI:10.1021/tx0155092
日期:2001.9.1
approximately 10(-9) M(-1) s(-1) for the reactions of glyoxal and glycolaldehyde with dG, respectively. The kinetic results rule out contamination of 2-phosphoglycolaldehyde preparations with glyoxal as the basis for our observations. The rate constant for the formation of glyoxal from 2-phosphoglycolaldehyde (10(-8) s(-1)) is consistent with glyoxal generation being the rate-limiting step in the formation
DNA中脱氧核糖的氧化导致形成各种亲电子产物,这些产物可能与核碱基反应形成加合物。我们现在报道2-脱氧核糖醛,脱氧核糖核酸在DNA中的3'-氧化产生的3'-磷酸乙醛残基的模型,与dG和DNA反应形成dG的非对映体1,N2-乙二醛加合物3-(2 -脱氧-β-D-赤-戊呋喃基)-6,7-二氢-6,7-二羟基咪唑并[1,2-a]嘌呤-9(3H)-1。乙二醛加合物是在生物学条件下(pH 7.4和37摄氏度)形成的主要物质,还有一些次要的荧光加合物,包括1,N6-乙炔腺嘌呤。通过HPLC,质谱以及UV和NMR光谱对加合物进行了充分表征。2-磷酸乙二醛与dG的反应速率常数为10(-6)M(-1)s(-1),而速率常数为0.08和约10(-9)M(-1)s( -1)分别用于乙二醛和乙醇醛与dG的反应。动力学结果排除了乙二醛对2-磷酸乙二醇醛制剂的污染,这是我们观察的基础。由2-磷酸乙二醛(10(-8)s