Proteoglycans from chick limb bud chondrocyte cultures. Keratan sulfate and oligosaccharides which contain mannose and sialic acid.
Proteoglycans from chick limb bud chondrocyte cultures. Keratan sulfate and oligosaccharides which contain mannose and sialic acid.
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来自鸡肢芽软骨细胞培养物的蛋白多糖。
DOI：
10.1016/s0021-9258(18)43703-9
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发表时间：
1980
期刊：
影响因子：
--
通讯作者：
A. Caplan
中科院分区：
文献类型：
--
作者：
S. De Luca;L. S. Lohmander;B. Nilsson;V. Hascall;A. Caplan
前体[35 S]硫酸盐和[2- 3 H]甘露糖用于研究从鸡肢芽软骨细胞培养第8天分离的蛋白聚糖上硫酸角质素和其他寡糖的生物合成。经碱性硼氢化物处理后，用分子筛层析分离出三个含唾液酸的组分。第一种含有硫酸角质素，其通过用软骨素酶消化以除去硫酸软骨素，然后通过分子筛和离子交换色谱法纯化。纯化的硫酸角质素含有约8%的35 S活性。链的平均长度约为40个单糖，仅含有痕量的甘露糖（少于1个残基/3至4条链）。第二个馏分含有大部分的[3 H]甘露糖最初在单体中，但没有35 S活性。该级分似乎含有天冬酰胺-N-葡糖胺类型的寡糖-肽，因为不存在还原糖，并且碱性硼氢化物处理广泛降解了核心蛋白。低聚糖的组成，具有高比例的甘露糖，N-乙酰葡糖胺，半乳糖和唾液酸，与这一建议一致。第三部分由一系列寡糖组成，大小在3至6 μ m之间。它们含有N-乙酰半乳糖胺醇，表明它们通过N-乙酰半乳糖胺与丝氨酸和苏氨酸上的羟基之间的O-糖苷键连接到核心蛋白。因此，除了硫酸软骨素和硫酸角质素链之外，蛋白聚糖还含有两类寡糖，即糖蛋白特有的富含甘露糖的类和粘蛋白特有的O-糖苷类。
The precursors, [35S]sulfate and [2-3H]mannose, were used to study the biosynthesis of keratan sulfate and other oligosaccharides on proteoglycans isolated from Day 8 cultures of chick limb bud chondrocytes. After alkaline borohydride treatment, three fractions with sialic acid were separated by molecular sieve chromatography. The first contained keratan sulfate which was purified by digestion with chondroitinase to remove chondroitin sulfate, followed by molecular sieve and ion exchange chromatography. The purified keratan sulfate contained about 8% of the35S activity originally in monomer. The chains had an average length of about 40 monosaccharides and contained only trace amounts of mannose (less than 1 residue/three to four chains). The second fraction contained the majority of the [3H]mannose originally in monomer, but no35S activity. This fraction appears to contain oligosaccharide-peptides of the asparagine-N-glycosylamine type because there were no reduced sugars present and the alkaline borohydride treatment extensively degraded the core protein. The composition of the oligosaccharides, with high proportions of mannose, N-acetylglucosamine, galactose, and sialic acid, was consistent with this suggestion. The third fraction consisted of a series of oligosaccharides with sizes between three to six saccharides. They contained N-acetylgalactosaminitol, indicating that they were attached to the core protein by O-glycoside bonds between N-acetylgalactosamine and hydroxyl groups on serine and threonine. Thus, proteoglycans contain two classes of oligosaccharides, a mannose-rich class characteristic of glycoproteins and an O-glycoside class characteristic of mucins, in addition to the chondroitin sulfate and keratan sulfate chains.