Identification of novel proteins secreted by Lactobacillus plantarum that bind to mucin and fibronectin.
Lactobacillus plantarum is a lactic acid bacterium that can be isolated from a high variety of fermented foods, including dairy products. In the present work, eight novel proteins secreted by three L. plantarum strains have been identified by tandem mass spectrometry. Seven of them were predicted as extracellular proteins containing putative signal peptides. The sixth, identified as glyceraldehyde 3-phosphate dehydrogenase (GAPDH), is a cytoplasmic protein that has been detected on the surface of several microorganisms. Muramidase and GAPDH were secreted only by the L. plantarum BMCM12 strain. Two other bands present in this strain were not identified, in spite of their yielding good tryptic profiles, suggesting an absence of homolog sequences in the molecular databases. Four of these proteins, including GAPDH, bound to mucin and fibronectin. These proteins might play important roles in the physiology and ecology of this bacterium, notably in the interaction with the human host.
Sánchez
Borja
B
Université de Bordeaux, UMR 5248 CNRS, UBX1-ENITAB, ENITAB, Gradignan, France. b-sanchez@enitab.fr
Schmitter
Jean-Marie
JM
Urdaci
María C
MC
D001426:Bacterial Proteins / Q000302:isolation & purification* / Q000378:metabolism*; D005353:Fibronectins / Q000378:metabolism*; D006801:Humans; D048191:Lactiplantibacillus plantarum / Q000378:metabolism*; D013058:Mass Spectrometry / Q000379:methods; D009077:Mucins / Q000378:metabolism*; D011485:Protein Binding; D021382:Protein Sorting Signals
D001426:Bacterial Proteins; D005353:Fibronectins; D009077:Mucins; D021382:Protein Sorting Signals