单链寡脱氧核糖核苷酸是来自大肠杆菌的Fpg蛋白的底物。
Single-stranded oligodeoxyribonucleotides are substrates of Fpg protein from Escherichia coli.
作者信息
Ishchenko A A, Bulychev N V, Maksakova G A, Johnson F, Nevinsky G A
机构信息
Novosibirsk Institute of Bioorganic Chemistry, Siberian Division of the Russian Academy of Sciences, Russian Federation.
出版信息
IUBMB Life. 1999 Dec;48(6):613-8. doi: 10.1080/713803570.
The interaction of Escherichia coli Fpg protein, which catalyzes excision of several damaged purine bases including 8-oxoguanine (oxoG) from DNA with a set of single- (ss) and double-stranded (ds) 23-mer oligodeoxyribonucleotides (ODNs) containing 8-oxoguanine(s) at various positions, has been investigated. The affinities of different ss ODNs (KM = 0.55-1.3 microM) were shown to be 12-170 times less than those for corresponding ds ODNs (KM = 6-60 nM). Depending on the position of the oxoG within the ODNs, relative initial rates of conversion of ss substrates may be less than, comparable, or greater than those for ds ODNs. The enzyme can remove 5'-terminal oxoG from ODNs only if the 5'-end is phosphorylated. Fpg does not release oxoG residues from the ultimate and penultimate 3'-terminal positions. Duplexes containing two adjacent oxoG are poor substrates for the glycosylase.
研究了大肠杆菌Fpg蛋白与一组单链（ss）和双链（ds）23聚体寡脱氧核糖核苷酸（ODN）的相互作用，该蛋白催化从DNA中切除包括8-氧鸟嘌呤（oxoG）在内的几种受损嘌呤碱基，这些ODN在不同位置含有8-氧鸟嘌呤。结果表明，不同单链ODN的亲和力（KM = 0.55 - 1.3 microM）比相应双链ODN的亲和力（KM = 6 - 60 nM）低12 - 170倍。根据oxoG在ODN中的位置，单链底物的相对初始转化率可能低于、相当或高于双链ODN的转化率。只有当5'-末端磷酸化时，该酶才能从ODN中去除5'-末端的oxoG。Fpg不会从倒数第一个和倒数第二个3'-末端位置释放oxoG残基。含有两个相邻oxoG的双链体是糖基化酶的不良底物。
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