title: Characterization of Neospora caninum protease, NcSUB1 (NC-P65), with rabbit anti-N54.
abstract: NcSUB1 (formerly known as NC-p65) is the first molecularly described proteolytic enzyme of the intracellular protozoan parasite Neospora caninum. This report describes the characterization of a rabbit anti-N54, which is an antiserum generated against an internal fragment of NcSUB1 (amino acids 649-783). In immunofluorescence studies rabbit and-N54 labeled the apical end of the fixed parasite. By immuno-gold electron microscopy, the antibody bound primarily to the microneme organelles of the parasite. Analysis of secreted parasitic proteins indicated that a protein of molecular weight 65 kDa (reduced) or 55 kDa (nonreduced) was recognized bythe antibody. The same secreted proteins were affinity purified with rabbit anti-N54-coupled resins and were shown to contain major proteolytic activity by zymography. Thus, rabbit anti-N54 is the first antibody developed for N. caninum that binds to themicroneme proteins and recognizes a major secreted enzyme.
authors.affiliation: Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, One Shields Avenue, Davis, California 95616, USA.
authors.forename: Kitland
authors.initials: K
authors.lastname: Louie
authors.forename: Robert
authors.initials: R
authors.lastname: Nordhausen
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Robinson
authors.forename: Bradd C
authors.initials: BC
authors.lastname: Barr
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Conrad
mesh_terms: D000818:Animals; D000953:Antigens, Protozoan / Q000276:immunology; D002522:Chlorocebus aethiops; D010450:Endopeptidases / Q000737:chemistry / Q000276:immunology*; D005455:Fluorescent Antibody Technique; D006863:Hydrogen-Ion Concentration; D007106:Immune Sera / Q000276:immunology; D015151:Immunoblotting; D007150:Immunohistochemistry; D016253:Microscopy, Immunoelectron; D008970:Molecular Weight; D018688:Neospora / Q000201:enzymology* / Q000276:immunology; D011817:Rabbits; D014709:Vero Cells
chemical_list: D000953:Antigens, Protozoan; D007106:Immune Sera; D010450:Endopeptidases