Pujol F H, Cesari I M
Laboratorio de Inmunoparasitología, Centro de Microbiología y Biología Celular IVIC, Caracas, Venezuela.
Membr Biochem. 1993 Jul-Sep;10(3):155-61. doi: 10.3109/09687689309150262.
Lectins from Lens culinaris and Arachis hypogaea immobilized on polyacrylamide beads were used for selective isolation of glycosylated surface membrane domains of adult Schistosoma mansoni worms, and the method was compared with the membrane isolation procedure developed with polycationic (Affi-Gel) beads. The lentil lectin proved to be suitable for interaction with surface membrane components: an increment in the specific activities of tegumental phosphohydrolases was observed in the bound fraction with respect to that observed in a total worm homogenate. A characteristic polypeptide pattern on gel electrophoresis was also seen, more restricted than that obtained with the bound Affi-Gel fraction. Immobilized peanut lectin was not successful as a method for isolating membrane material from the tegument of adult worms. Solubilization and dissociation of the lentil lectin-bound enzyme markers was achieved after addition of detergent and competing sugars. Glycosylation of the solubilized enzymes was further confirmed by affinity chromatography with fresh lentil lectin-coated beads. These results, together with histochemical evidences, suggest that the active sites of some of these enzymes are located within or close to the cytoplasmic leaflet of the surface tegumental membranes, and allow us to propose a model for the double surface membrane complex where some proteins may be crossing the two bilayers.
将来自兵豆和花生的凝集素固定在聚丙烯酰胺珠上，用于选择性分离曼氏血吸虫成虫的糖基化表面膜结构域，并将该方法与用聚阳离子（Affi-Gel）珠开发的膜分离程序进行比较。结果表明，小扁豆凝集素适合与表面膜成分相互作用：与全虫匀浆相比，结合部分的皮层磷酸水解酶比活性有所增加。凝胶电泳上也出现了特征性的多肽图谱，比Affi-Gel结合部分得到的图谱更具局限性。固定化花生凝集素作为从成虫皮层分离膜材料的方法并不成功。加入去污剂和竞争糖后，小扁豆凝集素结合的酶标记物得以溶解和解离。用新鲜的小扁豆凝集素包被的珠子进行亲和层析进一步证实了溶解酶的糖基化。这些结果与组织化学证据一起表明，其中一些酶的活性位点位于表面皮层膜的细胞质小叶内或附近，并使我们能够提出一个双表面膜复合体模型，其中一些蛋白质可能穿过两个双层膜。
