The redox potential interferes with the expression of laminin binding molecules in Bacteroides fragilis

• Published in: Memórias do Instituto Oswaldo Cruz Vol. 103; no. 7; pp. 683 - 689
• Main Authors: Ferreira, Eliane de Oliveira, Yates, Edwin Alexander, Goldner, Morris, Vommaro, Rossiane Cláudia, Silva Filho, Fernando Costa e, Petrópolis, Débora Barreiros, Domingues, Regina M C Pilotto
• Format: Journal Article
• Language: English
• Published: Brazil Instituto Oswaldo Cruz, Ministério da Saúde 01-11-2008; Fundação Oswaldo Cruz (FIOCRUZ)
• Subjects: adhesion; Antibodies, Monoclonal; Bacterial Adhesion; Bacterial Outer Membrane Proteins - metabolism; Bacteroides fragilis; Bacteroides fragilis - growth & development; Bacteroides fragilis - metabolism; Bacteroides fragilis - ultrastructure; Carrier Proteins - metabolism; Extracellular Matrix - metabolism; Immunoblotting; Laminin - metabolism; laminin binding proteins; Microscopy, Electron, Transmission; outer membrane proteins; Oxidation-Reduction; PARASITOLOGY; Polysaccharides, Bacterial - metabolism; redox potential; Time Factors; TROPICAL MEDICINE; redox potential; outer membrane proteins; laminin binding proteins; adhesion; Bacteroides fragilis
• ISSN: 0074-0276; 1678-8060; 1678-8060; 0074-0276
• DOI: 10.1590/S0074-02762008000700010

The Bacteroides fragilis ATCC strain was grown in a synthetic media with contrasting redox potential (Eh) levels [reduced (-60 mV) or oxidised (+100 mV)] and their adhesion capacity to extracellular matrix components was evaluated. The strain was capable of adhering to laminin, fibronectin, fibronectin + heparan sulphate and heparan sulphate. A stronger adherence to laminin after growing the strain under oxidising conditions was verified. Electron microscopy using ruthenium red showed a heterogeneous population under this condition. Dot-blotting analyses confirmed stronger laminin recognition by outer membrane proteins of cells cultured at a higher Eh. Using a laminin affinity column, several putative laminin binding proteins obtained from the cultures kept under oxidising (60 kDa, 36 kDa, 25 kDa and 15 kDa) and reducing (60 kDa) conditions could be detected. Our results show that the expression of B. fragilis surface components that recognise laminin are influenced by Eh variations.