Structures of Oligomannoside Chains of α-Mannosidase from Porcine Kidney
Structures of Oligomannoside Chains of α-Mannosidase from Porcine Kidney
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猪肾α-甘露糖苷酶寡甘露糖苷链的结构
DOI：
10.1093/oxfordjournals.jbchem.a135589
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发表时间：
1986
影响因子：
2.7
通讯作者：
J. Vliegenthart
中科院分区：
文献类型：
--
作者：
Y. Kozutsumi;Y. Nakao;T. Teramura;T. Kawasaki;Ikuo Yamashiina;J. H. Mutsaers;H. Halbeek;J. Vliegenthart
猪肾中的溶酶体酸性α-甘露糖苷酶含有甘露糖（4.8%）、半乳糖（0.9%）、岩藻糖（0.5%）、N-乙酰葡糖胺（3.1%）和甘露糖6-磷酸（0.1%）。内切-β-N-乙酰氨基葡萄糖苷酶-H（endo-H）可释放寡糖链中约50%的总己糖。它们主要是中性的，低聚甘露糖苷型寡糖含有5，6和9甘露糖残基，分别在百分之36：25：34的比例。500-MHz 1H-NMR光谱结合还原化合物的顺序外切糖苷酶消化揭示了三个级分中的每一个仅由单一异构体组成; Man 9化合物具有以下结构：（式：参见tex）。Man 6-化合物缺乏Man残基D1、D2和D3，而Man 5-化合物也缺乏Man-C。除了中性的，一些（5%）磷酸化的低聚甘露糖苷型寡糖得到。对endo-H抗性糖肽进行肼解。肼释放的寡糖中约有60%是相当小的，其组成可以表示为Man 2 -3GlcNAc[Fuc]0-1GlcNAcol。其余40%由较大尺寸的含半乳糖的N-乙酰乳糖胺型寡糖组成。对高度纯化的小分子化合物进行的包括连续外切糖苷酶消化和500 MHz 1H-NMR光谱的研究揭示了内-H抗性寡糖的以下四种结构：（式：见正文）。
: Lysosomal acid alpha-mannosidase from porcine kidney was found to contain mannose (4.8%), galactose (0.9%), fucose (0.5%), N-acetylglucosamine (3.1%), and mannose 6-phosphate (0.1%). Approximately 50% of the total hexose of the oligosaccharide chains could be released by endo-beta-N-acetylglucosaminidase-H (endo-H). They were predominantly neutral, oligomannoside-type oligosaccharides containing 5, 6, and 9 mannose residues, respectively, in the centesimal ratio of 36:25:34. 500-MHz 1H-NMR spectroscopy in conjunction with sequential exoglycosidase digestion of the reduced compounds revealed that each of the three fractions consisted of a single isomer only; the Man9 compound has the following structure: (Formula: see tex). The Man6-compound lacks Man residues D1, D2, and D3, while the Man5-compound lacks Man-C as well. In addition to the neutral ones, some (5%) phosphorylated oligomannoside-type oligosaccharides were obtained. The endo-H resistant glycopeptides were subjected to hydrazinolysis. Approximately 60% of the oligosaccharides released by hydrazine were found to be of rather small size; their composition can be represented asMan2-3GlcNAc[Fuc]0-1GlcNAcol. The remaining 40% consist of larger-size galactose-containing, N-acetyllactosamine-type oligosaccharides. Studies involving sequential exoglycosidase digestion and 500-MHz 1H-NMR spectroscopy performed on the highly purified small-sized compounds revealed the following four structures for the endo-H-resistant oligosaccharides: (Formula: see text).