Coombe D R, Jakobsen K B, Parish C R
Exp Cell Res. 1987 Jun;170(2):381-401. doi: 10.1016/0014-4827(87)90315-6.
Molecules binding sulfated polysaccharides were detected as lectins in cholate lysates of cells from twelve sponge species. Each species exhibited a unique binding profile. The pattern of binding indicated that the specificity was most probably determined by the orientation of the sulfate groups on the polysaccharide chains. Cells from each of the three species examined in more detail were found to express sulfated polysaccharide-binding molecules at their surface and at least one of the polysaccharides recognized was found to inhibit the reaggregation of cells from each species. Moreover, in all but one instance, lectins for the inhibitory polysaccharide were both detected in cell lysates and shown to be expressed at the cell surface. Sulfated polysaccharides, therefore, appeared to be involved in cell interaction events in the Porifera. This conclusion was confirmed by the isolation via ion exchange chromatography of an endogenous polysaccharide from an O. tenuis cell extract. This molecule contained uronic acid and hexose units in a ratio of 2:1, 11.9% sulfur and less than 0.5% protein. It inhibited the aggregation of O. tenuis cells and the agglutination of dextran-sulfate- and polyvinyl-sulfate-coupled erythrocytes by O. tenuis cell lysates. O. tenuis cell aggregation was also inhibited by polyvinyl sulfate and dextran sulfate and molecules binding these compounds were expressed on the surface of O. tenuis cells. Thus, is was probable that the cell surface receptor for polyvinyl sulfate and dextran sulfate and isolated sponge sulfated polysaccharide are one and the same. Finally, using a dextran sulfate affinity procedure, a 35 kD dextran-sulfate-binding protein was isolated from the surface of O. tenuis cells. The possibility that the polysaccharide isolated from O. tenuis cell extracts in the absence of calcium is the monomeric form of a cell aggregation-enhancing factor is discussed.
在来自12种海绵物种的细胞胆酸盐裂解物中，检测到与硫酸化多糖结合的分子为凝集素。每个物种都表现出独特的结合模式。结合模式表明，特异性很可能由多糖链上硫酸基团的方向决定。对三个物种进行更详细检查发现，每个物种的细胞表面都表达硫酸化多糖结合分子，并且发现至少一种被识别的多糖可抑制每个物种细胞的再聚集。此外，除了一个实例外，在所有情况下，细胞裂解物中均检测到抑制性多糖的凝集素，并且显示其在细胞表面表达。因此，硫酸化多糖似乎参与了多孔动物门中的细胞相互作用事件。通过离子交换色谱法从纤细奥氏海绵细胞提取物中分离出一种内源性多糖，证实了这一结论。该分子中糖醛酸和己糖单元的比例为2:1，含硫量为11.9%，蛋白质含量低于0.5%。它抑制了纤细奥氏海绵细胞的聚集以及纤细奥氏海绵细胞裂解物对硫酸葡聚糖和硫酸聚乙烯偶联红细胞的凝集作用。硫酸聚乙烯和硫酸葡聚糖也抑制了纤细奥氏海绵细胞的聚集，并且结合这些化合物的分子在纤细奥氏海绵细胞表面表达。因此，硫酸聚乙烯和硫酸葡聚糖的细胞表面受体与分离出的海绵硫酸化多糖很可能是同一物质。最后，使用硫酸葡聚糖亲和方法，从纤细奥氏海绵细胞表面分离出一种35kD的硫酸葡聚糖结合蛋白。讨论了在无钙情况下从纤细奥氏海绵细胞提取物中分离出的多糖是细胞聚集增强因子单体形式的可能性。
