Domain structure of heparan sulfates from bovine organs
Domain structure of heparan sulfates from bovine organs
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DOI：
10.1074/jbc.271.30.17804
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发表时间：
1996-07-26
影响因子：
4.8
通讯作者：
Lindahl, U
中科院分区：
文献类型：
--
作者：
Maccarana, M;Sakura, Y;Lindahl, U
从牛主动脉、肺、肠和肾中分离出硫酸肝素样品，通过混合肝素酶消化或硝酸处理，进行或不进行n -去乙酰化，对所得寡糖的分析表明，各种硫酸肝素样品都含有多达8或9个连续的n -乙酰化氨基葡萄糖残基区域，以及连续的n -硫酸序列。在后一种结构中，l -依糖醛酸在总己糖醛酸单位中所占的比例非常稳定，为50-60%。在所有的伊杜醛酸单元中，36-55%位于相邻的n -硫酸化区之外，可能是由n -乙酰化和n -硫酸化双糖残基交替组成的序列。虽然n -硫酸块内的大多数伊杜醛酸单元是2- o -硫酸化的，但位于外部的伊杜醛酸单元几乎完全是非硫酸化的。硫酸肝素制剂在6- o -硫酸氨基葡萄糖单元的含量方面存在显著差异，其中一半以上位于n -硫酸块区域之外。这些发现表明，伊杜醛酸残基的形成及其随后的2-O-硫酸化在硫酸肝素链的连续n -硫酸化区域内偶联，而不是在其外部，此外，在硫酸肝素生物合成过程中，2-O和6- o -硫转移酶反应受到不同的调节。
Samples of heparan sulfate, isolated from bovine aorta, lung, intestine, and kidney, were degraded by digestion with a mixture of heparitinases or by treatment with nitrous acid, with or without previous N-deacetylation, Analysis of the resulting oligosaccharides showed that the various heparan sulfate samples all contained regions of up to 8 or 9 consecutive N-acetylated glucosamine residues, as well as contiguous N-sulfated sequences. L-Iduronic acid accounted for a remarkably constant proportion, 50-60%, of the total hexuronic acid units within the latter structures. Of the total iduronic acid units, 36-55% were located outside the contiguous N-sulfated regions, presumably in sequences composed of alternating N-acetylated and N-sulfated disaccharide residues. While most of the iduronic acid units within the N-sulfated blocks were 2-O-sulfated, those located outside were almost exclusively nonsulfated. The heparan sulfate preparations differed markedly with regard to the content of 6-O-sulfated glucosamine units, more than half of which were located outside the N-sulfated block regions. These findings suggest that the formation of iduronic acid residues and their subsequent 2-O-sulfation are coupled within but not outside the contiguous N-sulfated regions of the heparan sulfate chains and, furthermore, that the 2-O- and 6-O-sulfotransferase reactions are differentially regulated during heparan sulfate biosynthesis.