title: [Antigens specific to pre-cysts and in vivo chitin synthetase activity in Entamoeba invadens].
abstract: In this paper we studied the transformation of a trophozoite into a cyst in Entamoeba, using E. invadens as a model. We had the following objectives: a) identification of precyst-specific proteins (P), by a monoclonal antibody against E. invadens and heterologous polyclonal antibodies against cellular (165) fractions of Mucar rouxii, which are chitin synthetase activity rich; and b) in vivo determination of the time required for the expression of activity of the chitin synthetase during encystment. We found P markers which are not found in either trophozoites nor cysts. Monoclonal F507 antibody recognized a 33 kDa protein in P and the polyclonal anti-16S antibodies reacted with a 90 kDa protein to P. Even though the 33 and 90 kDa proteins have a different molecular weight from the chitin synthetase described in fungi (57 kDa and 65 kDa) and yeasts (63 kDa), we conclude that these proteins are specific to P and that the 90 kDa one shares epitopes with chitosomal fractions of M. rouxii. Also, the mayor accumulation of alkali-resistant material, sensitive to chitinase, occurred during the formation of P, between 40 and 50 hours post incubation, during encystment. One may conclude that chitin polymers are synthesized during the P phase.
authors.affiliation: Depto. de Genética y Biología Molecular, I.P.N., México, D.F.
authors.forename: J
authors.initials: J
authors.lastname: Valdés
authors.forename: E
authors.initials: E
authors.lastname: López-Romero
authors.forename: E
authors.initials: E
authors.lastname: Orozco
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000913:Antibodies, Protozoan / Q000276:immunology; D000918:Antibody Specificity; D000953:Antigens, Protozoan / Q000276:immunology*; D002686:Chitin / Q000096:biosynthesis; D002687:Chitin Synthase / Q000032:analysis*; D004747:Entamoeba / Q000201:enzymology / Q000254:growth & development / Q000276:immunology*; D000939:Epitopes / Q000276:immunology; D011108:Polymers; D015800:Protozoan Proteins / Q000032:analysis* / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D000939:Epitopes; D011108:Polymers; D015800:Protozoan Proteins; D002686:Chitin; D002687:Chitin Synthase
vernacular_title: Anígenos específicos de prequistes y activadad in vivo de quitina sintetasa en Entamoeba invadens.