title: Reattachment of surface array proteins to Campylobacter fetus cells.
abstract: Campylobacter fetus strains may be of serotype A or B, a property associated with lipopolysaccharide (LPS) structure. Wild-type C. fetus strains contain surface array proteins (S-layer proteins) that may be extracted in water and that are critical for virulence. To explore the relationship of S-layer proteins to other surface components, we reattached S-layer proteins onto S- template cells generated by spontaneous mutation or by serial extractions of S+ cells with water. Reattachment occurred in the presence of divalent (Ba2+, Ca2+, Co2+, and Mg2+) but not monovalent (H+, NH4+, Na+, K+) or trivalent (Fe3+) cations. The 98-, 125-, 127-, and 149-kDa S-layer proteins isolated from strains containing type A LPS (type A S-layer protein) all reattached to S- template cells containing type A LPS (type A cells) but not to type B cells. The 98-kDa type B S-layer protein reattached to SAP- type B cells but not to type A cells. Recombinant 98-kDa type A S-layer protein and its truncated amino-terminal 65- and 50-kDa segments expressed in Escherichia coli retained the full and specific determinants for attachment. S-layer protein and purified homologous but not heterologous LPS in the presence of calcium produced insoluble complexes. By quantitative enzyme-linked immunosorbent assay, the S-layer protein copy number per C. fetus cell was determined to be approximately 10(5). In conclusion, C. fetus cells are encapsulated by a large number of S-layer protein molecules which may be specifically attached through the N-terminal half of the molecule to LPS in the presence of divalent cations.
authors.affiliation: Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee 37232.
authors.forename: L Y
authors.initials: LY
authors.lastname: Yang
authors.forename: Z H
authors.initials: ZH
authors.lastname: Pei
authors.forename: S
authors.initials: S
authors.lastname: Fujimoto
authors.forename: M J
authors.initials: MJ
authors.lastname: Blaser
mesh_terms: D000818:Animals; D016667:Bacterial Capsules / Q000737:chemistry / Q000378:metabolism* / Q000648:ultrastructure; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry / Q000378:metabolism* / Q000648:ultrastructure; D001426:Bacterial Proteins; D002168:Campylobacter fetus / Q000737:chemistry / Q000378:metabolism* / Q000648:ultrastructure; D002412:Cations / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007526:Isoelectric Point; D008070:Lipopolysaccharides / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000737:chemistry / Q000378:metabolism* / Q000648:ultrastructure; D008854:Microscopy, Electron
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D002412:Cations; D008070:Lipopolysaccharides; D008562:Membrane Glycoproteins; C055764:S-layer proteins