PATTERNS OF URONOSYL EPIMERIZATION AND 4-/6-O-SULFATION IN CHONDROITIN/DERMATAN SULFATE FROM DECORIN AND BIGLYCAN OF VARIOUS BOVINE-TISSUES
PATTERNS OF URONOSYL EPIMERIZATION AND 4-/6-O-SULFATION IN CHONDROITIN/DERMATAN SULFATE FROM DECORIN AND BIGLYCAN OF VARIOUS BOVINE-TISSUES
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DOI：
10.1093/glycob/4.5.685
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发表时间：
1994-10-01
期刊：
影响因子：
4.3
通讯作者：
FRANSSON, LA
中科院分区：
文献类型：
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作者：
CHENG, F;HEINEGARD, D;FRANSSON, LA
皮聚糖硫酸盐是两种双糖重复序列的共聚物：d -葡萄糖醛酸- n -乙酰半乳糖胺和l -伊杜醛酸- n -乙酰半乳糖胺。前者可以在半乳糖胺的C-4或C-6处被o -硫酸盐化，而后者几乎只含有4- o -硫酸盐化的半乳糖胺。一小部分l -伊杜酸盐可在C-2处发生o -硫酸盐反应。硫酸软骨素不含l -伊杜酸重复序列。我们利用我们最近开发的半乳糖胺聚糖序列分析方法，研究了从各种牛组织（如真皮、巩膜、肌腱、主动脉、软骨和骨）中提取的蛋白聚糖decorin和biglycan的皮肤/硫酸软骨素的结构。在还原端放射性碘化的聚糖链，用特定的酶（软骨素裂解酶）进行部分裂解，并进行高分辨率聚丙烯酰胺凝胶电泳、印迹和放射自显影，以鉴定从标记的还原端延伸到裂解点的片段。我们使用软骨素B裂解酶来确定l -伊杜醛酸盐的位置，使用软骨素AC-I裂解酶来确定d -葡萄糖醛酸盐的位置，使用软骨素C裂解酶来进行裂解，其中d -葡萄糖醛酸盐残基被6- o硫酸盐n -乙酰半乳糖胺接替。我们可以证明这两种外周脲酸的组织特异性、周期性和波状分布模式，以及来自decorin或biglycan的皮肤硫酸盐的特定硫酸化模式。例如，一些皮肤硫酸盐含有富含n-葡萄糖醛酸的结构域，这些结构域总是被6-硫酸盐化（巩膜decorin），其他的总是被4-硫酸盐化（来自牛真皮、软骨和骨骼的decorin；来自主动脉的biglycan），或者在靠近连锁区域的地方被6-硫酸盐化，但在更远的区域（来自猪真皮和牛肌腱的decorin）被4-硫酸盐化。来自骨和关节软骨的Decorin以及来自关节和鼻软骨的biglycan主要携带硫酸软骨素链，但也携带一些皮肤硫酸，而来自鼻软骨聚集蛋白的半乳糖胺聚糖链则不含L-iduronate。来自同一组织（关节软骨或巩膜）的Decorin和biglycan具有相似的聚糖链。大聚糖分子的两个侧链也可能彼此相似。糖链中最靠近核心蛋白的部分被不同程度的带电基团取代，这可能与主链的结构特征有关。
Dermatan sulphate is a co-polymer of two types of disaccharide repeats: D-glucuronate-N-acetylgalactosamine and L-iduronate-N-acetylgalactosamine. The former can be O-sulphated at C-4 or C-6 of the galactosamine, whereas the latter contains almost exclusively 4-O-sulphated galactosamine. A minor proportion of the L-iduronate may be O-sulphated at C-2. Chondroitin sulphate has no L-iduronate- containing repeats. We have used our recently developed methods for sequence analysis of galactosaminoglycans to investigate the structure of dermatan/chondroitin sulphates of the proteoglycans decorin and biglycan derived from various bovine tissues, like dermis, sclera, tendon, aorta, cartilage and bone. The glycan chains, radioiodinated at the reducing end, were partially cleaved with specific enzymes (chondroitin lyases), and subjected to high-resolution polyacrylamide gel electrophoresis, blotting and autoradiography to identify fragments extending from the labelled reducing end to the point of cleavage. We used chondroitin B lyase to identify the location of L-iduronate, chondroitin AC-I lyase to locate D-glucuronate and chondroitin C lyase to cleave where D-glucuronate residues were succeeded by 6-O-sulphated N-acetylgalactosamine. We could demonstrate tissue-specific, periodic and wave-like patterns of distribution for the two epimeric uronic acids, as well as specific patterns of sulphation in dermatan sulphates derived from either decorin or biglycan. For example, some dermatan sulphates contained n-glucuronate-rich domains that were always 6-sulphated (scleral decorin), others were always 4-sulphated (decorin from bovine dermis, cartilage and bone; biglycan from aorta) or 6-sulphated near the linkage region, but 4-sulphated in more distal domains (decorin from porcine dermis and bovine tendon). Decorin from bone and articular cartilage, as well as biglycan from articular and nasal cartilage, carried largely chondroitin sulphate chains, but also some dermatan sulphate, whereas galactosaminoglycan chains derived from aggrecan of nasal cartilage were free of L-iduronate. Decorin and biglycan from the same tissue (articular cartilage or sclera) had similar glycan chains. The two side chains in a biglycan molecule are probably also similar to one another. The portion of the glycan chains nearest to the core protein was substituted with charged groups to a variable degree, which may correlate with the structural features of the main chain.