Structural basis for the substrate specificity of endo-beta-N-acetylglucosaminidase F(3).
Structural basis for the substrate specificity of endo-beta-N-acetylglucosaminidase F(3).
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DOI：
10.1021/bi0001731
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发表时间：
2000-06
期刊：
影响因子：
2.9
通讯作者：
C. Waddling;T. Plummer;A. Tarentino;P. Van Roey
中科院分区：
文献类型：
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作者：
C. Waddling;T. Plummer;A. Tarentino;P. Van Roey
Endo-β- n -乙酰氨基葡萄糖苷酶F3可切割天冬酰胺连接的低聚糖核心GlcNAc之间的β(1−4)连接，对双天线和三天线复合聚糖具有特异性。Endo F3及其配合物及其反应产物双触角八糖Gal-β(1−4)-GlcNAc-β(1−2)-Man-α(1−3)[Gal-β(1−4)-GlcNAc-β(1−2)-Man-α(1−6)]-Man-β(1−4)-GlcNAc，分别测定了1.8和2.1 A的晶体结构。将高甘露糖寡糖特异性蛋白Endo F3与高甘露糖寡糖特异性蛋白Endo F1的结构进行比较，发现其寡糖识别位点的折叠和氨基酸组成高度不同。低聚糖与蛋白质的结合不影响蛋白质的构象。该低聚糖的构象与其他双天线低聚糖相似，除了两个连接：α(1−3)分支的Gal-β(1−4)-GlcNAc连接和α(1−6)分支的GlcNAc-β(1−2)-Man连接。尤其是后者……
Endo-β-N-acetylglucosaminidase F3 cleaves the β(1−4) link between the core GlcNAc's of asparagine-linked oligosaccharides, with specificity for biantennary and triantennary complex glycans. The crystal structures of Endo F3 and the complex with its reaction product, the biantennary octasaccharide, Gal-β(1−4)-GlcNAc-β(1−2)-Man-α(1−3)[Gal-β(1−4)-GlcNAc-β(1−2)-Man-α(1−6)]-Man-β(1−4)-GlcNAc, have been determined to 1.8 and 2.1 A resolution, respectively. Comparison of the structure of Endo F3 with that of Endo F1, which is specific for high-mannose oligosaccharides, reveals highly distinct folds and amino acid compositions at the oligosaccharide recognition sites. Binding of the oligosaccharide to the protein does not affect the protein conformation. The conformation of the oligosaccharide is similar to that seen for other biantennary oligosaccharides, with the exception of two links: the Gal-β(1−4)-GlcNAc link of the α(1−3) branch and the GlcNAc-β(1−2)-Man link of the α(1−6) branch. Especially the latter li...