Localization of sugar-binding proteins in Trypanosoma cruzi using gold-labeled neoglycoproteins.
Neoglycoproteins labeled with colloidal gold particles were used for the ultrastructural localization of sugar-binding sites in epimastigote, amastigote and trypomastigote forms of Trypanosoma cruzi. Binding sites for N-acetyl-D-glucosamine and D-galactose were seen on the surface of about 80% and 5 to 10% of the trypomastigote forms, respectively. They were inhibited by addition of the respective monosaccharides to the incubation medium. Binding sites for D-mannose were not observed in trypomastigotes. No labeling of the surface of amastigote and epimastigote forms was observed with the neoglycoproteins which bind to N-acetyl-D-glucosamine, D-galactose and D-mannose-binding sites. Labeling of the nucleus and the kinetoplast with the neoglycoprotein which recognizes N-acetyl-D-glucosamine binding sites was observed. The results obtained are discussed in relation to the possible role which surface sugar binding sites play in the process of T. cruzi-host cell interaction.
Degett
J
J
Laboratório de Ultraestrutura Celular, Universidade Federal do Rio de Janeiro, Brasil.
Souto-Padron
T
T
De Souza
W
W
D000117:Acetylglucosamine / Q000378:metabolism; D000818:Animals; D001665:Binding Sites; D050260:Carbohydrate Metabolism; D005690:Galactose / Q000378:metabolism; D006023:Glycoproteins / Q000032:analysis*; D006046:Gold; D008854:Microscopy, Electron; D014349:Trypanosoma cruzi / Q000032:analysis* / Q000254:growth & development / Q000648:ultrastructure
D006023:Glycoproteins; D006046:Gold; D000117:Acetylglucosamine; D005690:Galactose