Albano R M, Mourão P A
J Biol Chem. 1986 Jan 15;261(2):758-65.
The sulfated glycans in the tunic of Styela plicata differ from the glycosaminoglycans of animal tissues and also from the sulfated polysaccharides isolated from marine algae. The ascidian glycans occur primarily as three fractions that differ markedly in molecular weight and chemical composition. The high molecular weight fraction encompasses a broad range of molecular weights but is chemically homogeneous and contains an unusual amount of galactose. The 20,000 molecular weight polysaccharide is rich in galactose and glucose while the 8,000 molecular weight fraction is rich in amino sugars and contains the neutral hexoses galactose, glucose, and mannose. All fractions contain large amounts of sulfate esters. The ascidians polysaccharides can be extracted from the tissue by proteolytic enzyme or by guanidine hydrochloride solutions. The high molecular weight fraction is preferentially extracted by papain while guanidine hydrochloride removes mainly the low molecular weight polysaccharides. We speculate that these sulfated glycans are essential for maintaining the structural integrity of the tunic, in analogy with the glycosaminoglycans of vertebrate connective tissues.
皱瘤海鞘被囊中硫酸化聚糖不同于动物组织中的糖胺聚糖，也不同于从海藻中分离出的硫酸化多糖。海鞘聚糖主要以三个组分存在，其分子量和化学组成差异显著。高分子量组分涵盖了广泛的分子量范围，但化学性质均一，且含有异常数量的半乳糖。分子量为20,000的多糖富含半乳糖和葡萄糖，而分子量为8,000的组分富含氨基糖，并含有中性己糖半乳糖、葡萄糖和甘露糖。所有组分都含有大量的硫酸酯。海鞘多糖可以通过蛋白水解酶或盐酸胍溶液从组织中提取出来。高分子量组分优先被木瓜蛋白酶提取，而盐酸胍主要去除低分子量多糖。我们推测，这些硫酸化聚糖对于维持被囊的结构完整性至关重要，这与脊椎动物结缔组织中的糖胺聚糖类似。
