title: Thiol proteinase expression and pathogenicity of Entamoeba histolytica.
abstract: Expression of the 56-kilodalton (kDa) neutral thiol proteinase has been shown to correlate with the potential of clinical isolates of Entamoeba histolytica to produce invasive disease. A 56-kDa band was identified by gelatin substrate gel electrophoresis in 10 of 10 isolates from patients with colitis or amebic liver abscesses, but in only 1 of 10 isolates from asymptomatic patients. Pathogenic isolates appear capable of releasing significantly larger quantities of the proteinase, as measured by cleavage of a synthetic peptide substrate, ZRR-AMC (benzyloxy-carbonyl-arginine-arginine-4-amino-7-methylcoumarin). We have also shown that the proteinase is released during the course of clinical invasive amebic disease, as demonstrated by the presence of circulating antibodies detectable by enzyme-linked immunosorbent assay. These studies support the importance of the 56-kDa thiol proteinase in the pathogenesis of invasive amebiasis.
authors.affiliation: Department of Medicine, University of California, San Diego 92037.
authors.forename: S L
authors.initials: SL
authors.lastname: Reed
authors.forename: W E
authors.initials: WE
authors.lastname: Keene
authors.forename: J H
authors.initials: JH
authors.lastname: McKerrow
mesh_terms: D000562:Amebiasis / Q000469:parasitology*; D000818:Animals; D003546:Cysteine Endopeptidases / Q000032:analysis / Q000096:biosynthesis*; D004404:Dysentery, Amebic / Q000469:parasitology; D004591:Electrophoresis, Polyacrylamide Gel; D004592:Electrophoresis, Starch Gel; D004748:Entamoeba histolytica / Q000201:enzymology* / Q000472:pathogenicity; D004749:Entamoebiasis / Q000469:parasitology*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D008101:Liver Abscess, Amebic / Q000469:parasitology
chemical_list: D003546:Cysteine Endopeptidases