Characterization of the oligosaccharides of prolyl hydroxylase, a microsomal glycoprotein.
Characterization of the oligosaccharides of prolyl hydroxylase, a microsomal glycoprotein.
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DOI：
10.1021/bi00342a040
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发表时间：
1985-10
期刊：
影响因子：
2.9
通讯作者：
N. Kedersha;J. Tkacz;R. Berg
中科院分区：
文献类型：
--
作者：
N. Kedersha;J. Tkacz;R. Berg
脯氨酰羟化酶是一种四聚体糖蛋白，催化胶原蛋白生物合成中重要的翻译后修饰。从整个鸡胚（WCE）纯化的酶具有两个不同的亚基，α和β，并已被几种技术证明驻留在鸡胚成纤维细胞的内质网。这里描述的研究表明，较大的两个亚基（α）存在于两种形式的鸡胚成纤维细胞（CEF）;这两种形式的碳水化合物含量不同。较大的α亚基α '含有两个N-连接的高甘露糖寡糖，每个寡糖含有八个甘露糖单位;较小的亚基α含有一个七甘露糖N-连接寡糖。两种寡糖都可以被内切-β-N-乙酰葡糖胺糖苷酶H切割，并被α-甘露糖苷酶完全消化，产生甘露糖基-N-乙酰葡糖胺。
Prolyl hydroxylase is a tetrameric glycoprotein that catalyzes a vital posttranslational modification in the biosynthesis of collagen. The enzyme purified from whole chick embryos (WCE) possesses two nonidentical subunits, alpha and beta, and has been shown by several techniques to reside in the endoplasmic reticulum of chick embryo fibroblasts. The studies described here demonstrate that the larger of the two subunits (alpha) exists in two forms in chick embryo fibroblasts (CEF); these two forms differ in carbohydrate content. The larger alpha subunit, alpha', contains two N-linked high mannose oligosaccharides, each containing eight mannose units; the smaller subunit, alpha, contains a single seven-mannose N-linked oligosaccharide. Both oligosaccharides could be cleaved by endo-beta-N-acetylglucosaminidase H and completely digested with alpha-mannosidase to yield mannosyl-N-acetylglucosamine.