title: Pbp, a cell-surface exposed plasminogen binding protein of Bacteroides fragilis.
abstract: The Gram-negative anaerobic bacterium B. fragilis is a member of the commensal flora of the human intestine, but is also frequently found in severe intra-abdominal infections. Several B. fragilis virulence factors have been implicated in the development of these infections. A B. fragilis protein of circa 60-kDa was identified as a putative plasminogen binding protein (Pbp). The corresponding gene was located, cloned, sequenced and the subcellular localization of the protein was investigated. Pbp was both determined in the outer membrane of B. fragilis and of E. coli that expressed the cloned protein. Protease accessibility studies showed that the protein is expressed at the cell surface. Importantly, we demonstrated that Pbp is sufficient and required for plasminogen binding to whole cells in both E. coli and B. fragilis. Pbp-like proteins were also detected in some other Bacteroides subspecies. The role of this potential B. fragilis virulence factor in pathogenicity is discussed.
authors.affiliation: Department of Molecular Microbiology, Faculty of Earth and Life Sciences, VU-University Amsterdam de Boelelaan 1085, 1081 HV Amsterdam, The Netherlands.
authors.forename: Robert
authors.initials: R
authors.lastname: Sijbrandi
authors.forename: Michiel
authors.initials: M
authors.lastname: Stork
authors.forename: Joen
authors.initials: J
authors.lastname: Luirink
authors.forename: Ben R
authors.initials: BR
authors.lastname: Otto
mesh_terms: D000595:Amino Acid Sequence; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D001441:Bacteroides fragilis / Q000235:genetics* / Q000378:metabolism*; D015153:Blotting, Western; D002352:Carrier Proteins / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D003001:Cloning, Molecular; D030562:Databases, Protein; D004926:Escherichia coli / Q000378:metabolism; D015870:Gene Expression; D005798:Genes, Bacterial; D005822:Genetic Vectors; D006801:Humans; D010957:Plasmids; D010958:Plasminogen / Q000378:metabolism
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D002352:Carrier Proteins; C084529:plasminogen-binding protein, bacteria; D010958:Plasminogen