Inestrosa N C, Nader H B, Garrido J, Sampaio L O, Brandan E, Dietrich C P
J Neurosci Res. 1987;17(3):256-64. doi: 10.1002/jnr.490170309.
The basement membranes of the innervated surface of the electric organ of Discopyge tschudii present a high concentration of mucopolysaccharides as revealed by intense ruthenium red-positive reaction. Glycosaminoglycans (GAGs) were isolated and characterized from these pure basement membranes by using a combination of agarose gel electrophoresis and enzymatic degradation with specific enzymes. The isolated basement membrane showed a high concentration of GAGs (130 mg/g of dry tissue); of this amount 49% was hyaluronic acid, 24% was chondroitin-6-sulfate, 12% was heparan sulfate, and 14% was dermatan sulfate. Controlled digestion with heparinase and heparitinases I and II was used to study the structural features of the heparan sulfate. Four unsaturated disaccharide units were found in the heparan sulfate: disulfated, N-sulfated, N-acetylated, and N-acetylated O-sulfated disaccharides. The disaccharide units of the cholinergic heparan sulfate present a high amount of disulfated disaccharides and a low amount of N-acetylated O-sulfated disaccharides. The N-sulfated disaccharides, in contrast to the N-acetylated ones, were found through all the structure of the cholinergic heparan sulfate. Finally our work shows for the first time the presence of dermatan sulfate in the basal lamina of the electric organ.
杜氏电鲇（Discopyge tschudii）电器官受神经支配表面的基底膜呈现出高浓度的黏多糖，强烈的钌红阳性反应揭示了这一点。通过结合琼脂糖凝胶电泳和用特定酶进行酶促降解，从这些纯净的基底膜中分离并鉴定了糖胺聚糖（GAGs）。分离出的基底膜显示出高浓度的GAGs（130毫克/克干组织）；其中49%是透明质酸，24%是硫酸软骨素-6-硫酸盐，12%是硫酸乙酰肝素，14%是硫酸皮肤素。用肝素酶和肝素酶I及II进行的可控消化用于研究硫酸乙酰肝素的结构特征。在硫酸乙酰肝素中发现了四种不饱和二糖单元：双硫酸化、N-硫酸化、N-乙酰化和N-乙酰化O-硫酸化二糖。胆碱能硫酸乙酰肝素的二糖单元呈现出大量的双硫酸化二糖和少量的N-乙酰化O-硫酸化二糖。与N-乙酰化二糖相反，N-硫酸化二糖在胆碱能硫酸乙酰肝素的整个结构中都有发现。最后，我们的工作首次表明电器官基底层中存在硫酸皮肤素。
