Schistosoma mansoni: Surface Membrane Isolation with Lectin-Coated Beads

Abstract

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.

Characterization of phosphodiesterase-5 as a surface protein in the tegument of Schistosoma mansoni

“…This indicates that SmNPP-5, similar to its ortholog from rat [25], is a glycoprotein. These results agree with data from Pujol and Cesari, who isolated a surface membrane-bound complex from adult worms using lectin-coated beads, implying N-glicosylated components, which presented phosphodiesterase activity [38]. It is possible that SmNPP-5 is the enzyme responsible for the activity detected in those studies.…”

Detection of Schistosoma mansoni Membrane Antigens by Immunoblot Analysis of Sera of Patients from Low-Transmission Areas

“…For the aim of the present study, we selected 40 positive sera (by the above-mentioned tests) from the four different sites (see Table 1, below). We also selected and evaluated 36 sera from patients of the above endemic areas harboring other infectious agents (19 Parasites. Adult S. mansoni (Venezuelan JL strain) worms were obtained by perfusion (11) of hamsters infected with 400 cercariae 7 weeks before, washed in sterile saline, and frozen at Ϫ80°C until used.…”

“…Other studies provided evidence for the relevant antigenicity of some S. mansoni membrane components (22,27). Adult S. mansoni membrane-bound enzymes, like alkaline phosphatase, acid phosphatase, type I phosphodiesterase, and Ca 2ϩ -ATPase, present in n-butanol extracts (BE) (8,18,19), were shown to be antigenic when tested in enzyme immunoassays (9). The antigenic property of the S. mansoni alkaline phosphatase was used for the development of a new diagnostic test called an alkaline phosphatase immunoassay (APIA), which takes direct advantage of the intrinsic catalytic activity of the antigen.…”

Planarians to schistosomes: an overview of flatworm cell-types and regulators

“…For instance, the tegument forms a double lipid bilayer, a structure uniquely found in blood flukes, shortly after the parasites penetrate the skin (McLaren & Hockley, 1977). In addition, early studies of the tegument suggest that it can display host glycolipids presumably to evade detection (Goldring et al , 1976, 1977; Pujol & Cesari, 1993). Recently, schistosome stem cells and their deployment throughout the parasite life cycle has been recognized as a primary driver of transmission, homeostasis, reproduction and immune evasion (Collins et al , 2013, 2016; Wang et al , 2013, 2018; Collins & Collins, 2016; Wendt & Collins, 2016; Lee et al , 2020; Li et al , 2021; Nanes Sarfati et al , 2021).…”