A Bacteroides fragilis surface glycoprotein mediates the interaction between the bacterium and the extracellular matrix component laminin-1

• Published in: Research in microbiology 2006-12, Vol.157 (10), p.960-966
• Main Authors: de O. Ferreira, Eliane, Araújo Lobo, Leandro, Barreiros Petrópolis, Débora, dos S. Avelar, Kátia Eliane, Ferreira, Maria Candida, e Silva Filho, Fernando Costa, Domingues, Regina Maria C.P.
• Format: Article
• Language: English
• Subjects: Adhesins, Bacterial - metabolism; Bacterial Adhesion; Bacterial Outer Membrane Proteins - metabolism; Bacteroides fragilis; Bacteroides fragilis - chemistry; Bacteroides fragilis - metabolism; Bacteroides Infections - microbiology; Biological and medical sciences; Extracellular Matrix - chemistry; Extracellular matrix components; Fundamental and applied biological sciences. Psychology; Glycoprotein; Humans; Laminin - metabolism; Laminin-1; Membrane Glycoproteins - metabolism; Microbiology; Peptides - metabolism
• ISSN: 0923-2508; 1769-7123
• DOI: 10.1016/j.resmic.2006.09.005

The adherence of Bacteroides fragilis strains to immobilized laminin-1 (LMN-1) was investigated using this protein adsorbed onto glass. Among the 27 strains isolated from infectious processes and assayed, 13 presented strong adherence to LMN-1. Among them, two strains, MC2 and 1081, showed the strongest association, and for that reason they were selected for further studies in which adherence to this protein was confronted with both physical-chemical and enzymatic treatments, along with concurrence assays with the LMN-1 molecule itself and the LMN-1-residing amino acid sequences (RGD, IKVAV, YIGSR, AG73, A13 and C16). The chemical and enzymatic treatments resulted in sharp decreases in binding rates of those strains, and competition experiments with LMN-1- residing amino acids revealed that, except for RGD and A13, all the others were effective at reducing bacterial binding of the bacteria. The outer membrane proteins (OMPs) of B. fragilis were extracted and assayed onto dot-blotted LMN-1, and when the extracts were chemically treated, especially with metasodium periodate, a drastic reduction in bacterial binding occurred. Results of the latter assays clearly indicate that bacterial molecules involved in both recognition and binding of B. fragilis to LMN-1 are present in OMP extracts. Taken together, our results strongly indicate that a B. fragilis surface glycoprotein may play a key role in bacterial association with LMN-1.