title: Biochemical nature and cellular origin of amyloid enhancing factor (AEF) as determined by anti-AEF antibody.
abstract: Low ionic strength acidic buffer, Sephadex G-200 and Benzamidine-Sepharose (BZ) gel chromatography, have been used for the partial purification of alveolar hydatid cyst (AHC) induced amyloid enhancing factor (AEF). BZ-gel bound AEF (AEF-BZ) demonstrated AEF activity in the mouse bioassay, proteolytic activity against Hide powder azure showed two major and three minor peptides on SDS-PAGE. Pretreatment of AEF-BZ with 10 mM phenylmethylsulphonyl fluoride or 20 mM p-chloromercuribenzoic acid completely abolished its bioactivity in vivo and proteolytic activity in vitro. Polyclonal anti-AEF antibody (AAA) was generated which on passive transfer into mice completely abolished the bioactivity of both casein-induced, or AHC-induced AEF. The AAA absorbed on Sepharose gel conjugated to normal mouse serum developed one common precipitin band between AE and AEF-positive sera from AHC-infected and old retired mice and in immunostaining it bound to the cytoplasmic granular components of a majority of splenic and peritoneal leucocytes from AHC-infected mice. In contrast, only a few normal mouse leucocytes showed positive staining. We suggest that AEF, in all probability, is a serine/thiol protease of leucocyte origin whose intracellular and humoral concentrations increase significantly during amyloidosis. The role of lysosomal proteases and anti-AEF antibody which has been successfully generated for the first time is discussed with reference to the origin of AEF and its presumed biological function in amyloidogenesis.
authors.affiliation: Department of Microbiology and Immunology, McGill University, Montreal, Quebec, Canada.
authors.forename: K
authors.initials: K
authors.lastname: Alizadeh-Khiavi
authors.forename: Z
authors.initials: Z
authors.lastname: Ali-Khan
mesh_terms: D000682:Amyloid / Q000032:analysis*; D000818:Animals; D000906:Antibodies / Q000032:analysis; D002729:Chloromercuribenzoates / Q000494:pharmacology; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D006023:Glycoproteins / Q000032:analysis* / Q000037:antagonists & inhibitors / Q000276:immunology; D007116:Immunization, Passive; D008099:Liver / Q000032:analysis; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D010447:Peptide Hydrolases / Q000032:analysis; D010664:Phenylmethylsulfonyl Fluoride / Q000494:pharmacology; D013154:Spleen / Q000032:analysis; D020245:p-Chloromercuribenzoic Acid
chemical_list: D000682:Amyloid; D000906:Antibodies; D002729:Chloromercuribenzoates; D006023:Glycoproteins; C046748:amyloid enhancing factor; D010664:Phenylmethylsulfonyl Fluoride; D020245:p-Chloromercuribenzoic Acid; D010447:Peptide Hydrolases