Substrate Specificity of 2-Deoxy-<i>scyllo</i>-inosose Synthase, the Starter Enzyme for 2-Deoxystreptamine Biosynthesis, toward Deoxyglucose-6-phosphates and Proposed Mechanism
作者:Noriaki IWASE、Fumitaka KUDO、Noriaki YAMAUCHI、Katsumi KAKINUMA
DOI:10.1271/bbb.62.2396
日期:1998.1
A crucial enzyme in the biosynthesis of the 2-deoxystreptamine aglycon of clinically important aminocyclitol antibiotics is 2-deoxy-scyllo-inosose synthase (DOIS), which is responsible for the initial carbocycle formation of 2-deoxy-scyllo-inosose (1) from D-glucose-6-phosphate (G-6-P) (2). To get more insight into the mechanism and substrate specificity, deoxy-D-glucose-6-phosphates (deoxy-G-6-P)
在临床上重要的氨基环糖醇类抗生素的2-脱氧链胺糖苷配子生物合成中的关键酶是2-脱氧鞘氨醇合酶(DOIS),该酶负责最初的碳环形成2-脱氧鞘氨醇(1)的过程。 D-葡萄糖-6-磷酸酯(G-6-P)(2)。为了更深入地了解机理和底物特异性,化学合成了脱氧-D-葡萄糖-6-磷酸酯(脱氧-G-6-P)并使其与DOIS反应。该酶似乎使用2-脱氧-G-6-P和3-脱氧-G-6-P作为底物,它们都被转化为相应的双脱氧-鞘脂肌糖产物,但是4-脱氧-G-6-P未能环化由DOIS。这些结果清楚地支持了所提出的反应机制,该机制涉及G-6-P底物在C-4处的初始氧化。