Antigens specific to pre-cysts and in vivo chitin synthetase activity in Entamoeba invadens
Valdés, J.; López-Romero, E.; Orozco, E.
Archivos de Investigacion Medica 21(Suppl 1): 223-227
1990
ISSN/ISBN: 0066-6769 PMID: 1726662 Document Number: 349783
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.