Rumjanek F D, Campos E G, Afonso L C
Departamento de Bioquímica, Universidade Federal de Minas Gerais, Pampulha, Belo Horizonte, Brazil.
Mol Biochem Parasitol. 1988 Mar;28(2):145-52. doi: 10.1016/0166-6851(88)90062-x.
Schistosomula of Schistosoma mansoni were shown to contain proteins on their surface membranes which bind iodinated human low density lipoproteins (125I-LDL). Treatment of the parasites with trypsin decreased the binding in comparison with untreated controls. Membrane-bound, acetone-insoluble proteins were extracted from the schistosomula with Triton X-100 and the extract in liposome form was incubated with 125I-LDL at room temperature. After incubation a complex was formed between the proteins present in the extract and 125I-LDL, as shown by a filter binding assay. 125I-LDL binding to filters was proportional to the amount of protein in the extract; it was inhibited by unlabelled LDL and VLDL and by EDTA. Binding of 125I-LDL to proteins present in the liposome suspension containing the Triton X-100 extract followed saturation kinetics, indicating the occurrence of receptors for lipoproteins in the extract.
曼氏血吸虫的童虫被证明在其表面膜上含有能结合碘化人低密度脂蛋白（(^{125}I-LDL)）的蛋白质。与未处理的对照相比，用胰蛋白酶处理寄生虫会降低其结合能力。用Triton X-100从童虫中提取膜结合的、丙酮不溶性蛋白质，并将脂质体形式的提取物在室温下与(^{125}I-LDL)一起孵育。孵育后，通过滤膜结合试验表明提取物中的蛋白质与(^{125}I-LDL)之间形成了复合物。(^{125}I-LDL)与滤膜的结合与提取物中的蛋白质量成正比；它受到未标记的LDL和VLDL以及EDTA的抑制。(^{125}I-LDL)与含有Triton X-100提取物的脂质体悬浮液中存在的蛋白质的结合遵循饱和动力学，表明提取物中存在脂蛋白受体。
