Substrate specificities of rat liver microsomal glucosidases which process glycoproteins.
Substrate specificities of rat liver microsomal glucosidases which process glycoproteins.
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处理糖蛋白的大鼠肝微粒体葡萄糖苷酶的底物特异性。
DOI：
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发表时间：
1980
影响因子：
4.8
通讯作者：
P. Robbins
中科院分区：
文献类型：
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作者：
L. Grinna;P. Robbins
研究了大鼠肝微粒体葡萄糖苷酶I和II对Glc3-1Man9GlcNAc低聚糖的底物特异性。葡萄糖苷酶I和II与其寡糖底物的6‘-五羟甲基支链具有特定和必要的相互作用；当甘露糖残基从这一支链上去除时，活性降低。两种葡萄糖苷酶都对低聚糖底物还原端的特性做出反应；在脂连接和多肽连接的底物上的活性低于对游离低聚糖底物的活性。此外，葡萄糖苷酶似乎区分了与脂有关的低聚糖和与肽有关的低聚糖。我们的结论是，大鼠肝微粒体葡萄糖苷酶I和II除了与它们所降解的葡萄糖残基相互作用外，还与广泛的寡糖结构相互作用。
The substrate specificities of rat liver microsomal glucosidases I and II, which hydrolyze oligosaccharides of the composition Glc3-1Man9GlcNAc, were investigated. Glucosidases I and II were shown to have a specific and necessary interaction with the 6'-pentamannosyl branch of their oligosaccharide substrates; activity was reduced when mannose residues were removed from this branch. Both glucosidases responded to features at the reducing end of the oligosaccharide substrates; activity was lower towards lipid-linked and peptide-linked substrates than towards free oligosaccharide substrates. In addition, the glucosidases appeared to discriminate between oligosaccharides linked to lipid and oligosaccharides linked to peptide. We conclude that rat liver microsomal glucosidases I and II interact with extensive portions of oligosaccharide structure in addition to the glucose residues which they hydrolyze.