A base-off analogue of coenzyme-B12 with a modified nucleotide loop--1H-NMR structure analysis and kinetic studies with (R)-methylmalonyl-CoA mutase, glycerol dehydratase, and diol dehydratase.
A base-off analogue of coenzyme-B12 with a modified nucleotide loop--1H-NMR structure analysis and kinetic studies with (R)-methylmalonyl-CoA mutase, glycerol dehydratase, and diol dehydratase.
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辅酶 B12 的碱基类似物，具有修饰的核苷酸环 - 1 H-NMR 结构分析和 (R)-甲基丙二酸单酰辅酶 A 变位酶、甘油脱水酶和二醇脱水酶的动力学研究。
DOI：
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发表时间：
1997
期刊：
影响因子：
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通讯作者：
J. Rétey
中科院分区：
文献类型：
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作者：
L. Poppe;L. Poppe;E. Stupperich;W. Hull;T. Buckel;J. Rétey
(Co β-5'-脱氧腺苷-5'-基)-(对甲酚基)钴酰胺 (Ado-PCC) 是辅酶-B12 (CoB12) 碱基关闭形式的类似物，通过 (Co α/β-氰基/水)-(对甲酚基)钴酰胺 (PCC) 与 5'-氯-5'-脱氧腺苷的烷基化来制备。使用 COSY 和 NOESY 二维实验完全分析了 Ado-PCC 在 pH 7.4 下 D2O 中的 500 MHz 1H-NMR 谱。使用三种辅酶 B12 依赖性酶测试 Ado-PCC 的辅酶和抑制活性：(R)-甲基丙二酸单酰辅酶 A 变位酶、甘油脱水酶和二醇脱水酶。 Ado-PCC 对甲基丙二酸单酰辅酶 A 变位酶表现出很强的辅酶活性，已知该酶可结合 CoB12 的脱碱基形式。相比之下，Ado-PCC 没有辅酶活性，而是作为甘油脱水酶和二醇脱水酶的竞争性抑制剂，而甘油脱水酶和二醇脱水酶可能更喜欢 CoB12 的基础形式。这些结果表明，Ado-PCC的结构类似于CoB12的碱基关闭形式，可用于探讨辅酶B12依赖性酶的辅酶结合模式。
(Co beta-5'-Deoxyadenosin-5'-yl)-(p-cresolyl)cobamide (Ado-PCC), an analogue of the base-off form of coenzyme-B12 (CoB12), was prepared by alkylation of (Co alpha/beta-cyano/aqua)-(p-cresolyl)cobamide (PCC) with 5'-chloro-5'-deoxyadenosine. The 500 MHz 1H-NMR spectrum of Ado-PCC in D2O at pH 7.4 was completely analyzed using COSY and NOESY two-dimensional experiments. The coenzyme and inhibitory activities of Ado-PCC were tested with three coenzyme-B12-dependent enzymes: (R)-methylmalonyl-CoA mutase, glycerol dehydratase, and diol dehydratase. Ado-PCC showed strong coenzyme activity with methylmalonyl-CoA mutase, which is known to bind the base-off form of CoB12. In contrast, Ado-PCC had no coenzyme activity but acted instead as a competitive inhibitor with glycerol dehydratase and diol dehydratase, which are likely to prefer the base-on form of CoB12. These results indicate that Ado-PCC, whose structure is analogous to the base-off form of CoB12, can be used for probing the mode of coenzyme binding by coenzyme-B12-dependent enzymes.