title: Cell surface charge and sugar residues of Crithidia fasciculata and Crithidia luciliae.
abstract: The surface charge of Crithidia fasciculata and Crithidia luciliae was analysed by measurement of the zeta-potential and labelling of the protozoan surface with cationized ferritin particles. Both trypanosomatids have a net negative surface charge, with a zeta-potential of -10.39 mV and -11.12 mV for C. luciliae and C. fasciculata, respectively. Enzyme treatment showed that phosphate groups, but not sialic acid, significantly contributed to the negative surface charge. Lectin-induced agglutination was used to analyse the presence of surface-exposed carbohydrates in C. fasciculata and C. luciliae. The cells did not agglutinate when incubated in the presence of lectins which recognized L-fucose, N-acetyl-D-glucosamine and sialic acid. However, lectins which bind to N-acetyl-D-galactosamine, D-galactose and D-mannose agglutinated both protozoa.
authors.affiliation: Instituto de Biofísica Carlos Chagas Filho, Rio de Janeiro, Brasil.
authors.forename: M C
authors.initials: MC
authors.lastname: Motta
authors.forename: E M
authors.initials: EM
authors.lastname: Saraiva
authors.forename: F
authors.initials: F
authors.lastname: Costa e Silva Filho
authors.forename: W
authors.initials: W
authors.lastname: de Souza
mesh_terms: D000372:Agglutination Tests; D000818:Animals; D002241:Carbohydrates / Q000032:analysis*; D002462:Cell Membrane / Q000737:chemistry / Q000648:ultrastructure; D003421:Crithidia / Q000737:chemistry* / Q000648:ultrastructure; D016831:Crithidia fasciculata / Q000737:chemistry* / Q000648:ultrastructure; D006651:Histocytochemistry; D006863:Hydrogen-Ion Concentration; D037102:Lectins; D008854:Microscopy, Electron; D013499:Surface Properties
chemical_list: D002241:Carbohydrates; D037102:Lectins