title: Identification and characterization of Mycobacterium paratuberculosis recombinant proteins expressed in E. coli.
abstract: Mycobacterium paratuberculosis is the causative agent of Johne's disease, a chronic enteritis in ruminants, and it has also been isolated and identified from patients with Crohn's disease, an inflammatory bowel disease. The control of Johne's disease has been hampered by the lack of a reliable diagnostic test because of the large degree of antigenic cross-reactivity between mycobacterial and non-mycobacterial species. To help identify specific antigen(s) or epitope(s), an M. paratuberculosis expression library was screened with antibodies and DNA probes. In total, 54 clones were randomly picked, purified, and characterized by DNA probes and monoclonal antibodies with known specificity to individual mycobacterial antigens. Four clones carrying the heat shock protein 65K-, two representing the secreted protein 32K-, three representing the 21K-, and 20 clones representing the specific insertion element of M. paratuberculosis (IS900)-encoding genes and their gene products were identified and characterized. Well-defined recombinant antigens and/or epitopes representing M. paratuberculosis may facilitate the development of specific diagnostic tests and the investigation of their role in these chronic diseases.
authors.affiliation: Veterans Affairs Medical Center, Department of Medicine, Houston, Texas 77030.
authors.forename: F A
authors.initials: FA
authors.lastname: el-Zaatari
authors.forename: S A
authors.initials: SA
authors.lastname: Naser
authors.forename: L
authors.initials: L
authors.lastname: Engstrand
authors.forename: C Y
authors.initials: CY
authors.lastname: Hachem
authors.forename: D Y
authors.initials: DY
authors.lastname: Graham
mesh_terms: D000911:Antibodies, Monoclonal; D000942:Antigens, Bacterial / Q000276:immunology; D001426:Bacterial Proteins / Q000032:analysis / Q000235:genetics* / Q000276:immunology; D001483:Base Sequence; D003001:Cloning, Molecular; D003429:Cross Reactions; D017931:DNA Primers; D015342:DNA Probes; D004926:Escherichia coli / Q000235:genetics*; D008969:Molecular Sequence Data; D016927:Mycobacterium avium subsp. paratuberculosis / Q000235:genetics* / Q000276:immunology; D011994:Recombinant Proteins / Q000032:analysis / Q000235:genetics / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D017931:DNA Primers; D015342:DNA Probes; D011994:Recombinant Proteins