Souto-Padrón T, De Souza W
J Submicrosc Cytol. 1986 Oct;18(4):701-9.
The surface charge of epimastigote and trypomastigote forms of Trypanosoma cruzi was analysed by three approaches: a) visualization by electron microscopy of the binding of cationic particles (cationized ferritin at pH 7.2 and colloidal iron hydroxyde at pH 1.8) to the parasite's surface, b) visualization of the binding of fluorescein-labeled lectins (PNA and LPA) to the parasite's surface, and c) by cell electrophoresis. In all cases control, trypsin and neuraminidase-treated cells were analysed. The results obtained indicate that sialic acid residues located on the parasite's surface are responsible for the binding of cationic particles to it and the major component responsible for the net negative surface charge presented by T. cruzi. Phosphate groups, associated to phospholipids, also contribute to the negative surface charge. The effect of previous incubation of the parasites in the presence of lectins (ConA, WGA, PNA, RCA and LPA) on their surface charge was also analysed by cell electrophoresis.
a）通过电子显微镜观察阳离子颗粒（pH 7.2的阳离子铁蛋白和pH 1.8的胶体氢氧化铁）与寄生虫表面的结合，b）观察荧光素标记的凝集素（PNA和LPA）与寄生虫表面的结合，以及c）通过细胞电泳。在所有情况下，都对对照、经胰蛋白酶和神经氨酸酶处理的细胞进行了分析。获得的结果表明，位于寄生虫表面的唾液酸残基负责阳离子颗粒与其结合，并且是克氏锥虫呈现净负表面电荷的主要成分。与磷脂相关的磷酸基团也有助于负表面电荷的形成。还通过细胞电泳分析了寄生虫预先在凝集素（ConA、WGA、PNA、RCA和LPA）存在下孵育对其表面电荷的影响。
