Serodiagnostic reagent for entamoeba histolytica

摘要

The present invention is a composition of matter composed essentially of a purified homogeneous thiol proteinase secreted by Entamoeba histolytica trophozoites. In purified homogeneous form the neutral thiol proteinase has a subunit molecular weight of about 56,000+/-4,000, a neutral pH optimum, and an isoelectric point of about 6. The purified neutral thiol proteinase of the present invention can be obtained by using anion exchange and chromatofocusing Fast Protein Liquid Chromatography (FPLC) to purify the major neutral proteinase from secretions of axenically cultured Entamoeba histolytica trophozoites. The homogeneous neutral thiol proteinase of the present invention is immunogenic. It is useful as a serodiagnostic reagent for identifying the presence of antibodies in the sera of individuals exposed to Entamoeba histolytica trophozoites. The purified homogeneous enzyme can be used in ELISA assays or in other standard immunoassays.