We performed a biochemical and histochemical study of sulfated glycosaminoglycans in the tissues of the ascidian Styela plicata. A highly sulfated dermatan sulfate and a heparin-like polymer, identified by incubation with specific lyases, occur at different concentrations in intestine, heart, pharynx, and cloak. Dermatan sulfate prevails in the pharynx, whereas the heparin-like polymer abounds in the intestine. Staining of tissues sections with the cationic dye 1,9-dimethylmethylene blue before and after incubation with specific lyases revealed that the dermatan sulfate occurs in the extracellular matrix, while the heparin-like polymer is located within cytoplasmic granules of cells in the lumen of intestine and pharynx. The dermatan sulfate has a similar disaccharide composition in all tissues studied, whereas the heparin-like polymer differs in sulfate content. A direct relationship between sulfate content of the heparin-like polymer and antithrombin activity was observed. Analysis of the repeating disaccharide units of the heparin-like polymer indicates the presence of relatively high amounts of the disulfated disaccharide namely ΔUA-1→4-GlcN(SO4)-(6SO4), which may suggest the occurrence in ascidians of regulatory biosynthetic mechanisms different from those observed for heparin in mammals.
我们进行了对于尾索动物Styela plicata组织中
硫酸软骨素的生化和组织
化学研究。通过与特定裂解酶共同孵育,发现高度
硫酸化的
硫酸皮肤素和类似
肝素的聚合物在肠道、心脏、咽和外套膜中的浓度不同。
硫酸皮肤素在咽中占优势,而类似
肝素的聚合物在肠道中丰富存在。在使用
阳离子染料1,9-二甲基亚甲蓝对组织切片进行染色前后,我们发现
硫酸皮肤素存在于细胞外基质中,而类似
肝素聚合物位于肠道和咽腔内细胞的细胞质颗粒中。所有组织中的
硫酸皮肤素的二糖组成相似,而类似
肝素的聚合物在
硫酸盐含量上有所不同。我们观察到类似
肝素聚合物的
硫酸盐含量与抗凝血酶活性之间存在直接关系。对类似
肝素的聚合物重复二糖单元的分析表明,存在相对高量的双
硫酸化二糖,即ΔUA-1→4-GlcN(SO4)-(6SO4),这可能表明,尾索动物中存在不同于哺乳动物
肝素的调节性
生物合成机制。