A Bacteroides fragilis surface glycoprotein mediates the interaction between the bacterium and the extracellular matrix component laminin-1.
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.
de O Ferreira
Eliane
E
Departamento de Microbiologia Médica, UFRJ, Instituto de Microbiologia Prof Paulo de Góes, Ilha do Fundão, CEP 21941-590, Rio de Janeiro, Brazil. eliane_ferreirarj@yahoo.com
Araújo Lobo
Leandro
L
Barreiros Petrópolis
Débora
D
dos S Avelar
Kátia Eliane
KE
Ferreira
Maria Candida
MC
e Silva Filho
Fernando Costa
FC
Domingues
Regina Maria C P
RM
D018829:Adhesins, Bacterial / Q000378:metabolism; D001422:Bacterial Adhesion; D001425:Bacterial Outer Membrane Proteins / Q000378:metabolism*; D001442:Bacteroides Infections / Q000382:microbiology*; D001441:Bacteroides fragilis / Q000737:chemistry / Q000378:metabolism*; D005109:Extracellular Matrix / Q000737:chemistry; D006801:Humans; D007797:Laminin / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000378:metabolism*; D010455:Peptides / Q000378:metabolism
D018829:Adhesins, Bacterial; D001425:Bacterial Outer Membrane Proteins; D007797:Laminin; D008562:Membrane Glycoproteins; D010455:Peptides; C121346:laminin 1