Bifidobacterial enolase, a cell surface receptor for human plasminogen involved in the interaction with the host Candela, Marco and Biagi, Elena and Centanni, Manuela and Turroni, Silvia and Vici, Manuela and Musiani, Francesco and Vitali, Beatrice and Bergmann, Simone and Hammerschmidt, Sven and Brigidi, Patrizia,, 155, 3294-3303 (2009), doi = https://doi.org/10.1099/mic.0.028795-0, publicationName = Microbiology Society, issn = 1350-0872, abstract= The interaction with the host plasminogen/plasmin system represents a novel component in the molecular cross-talk between bifidobacteria and human host. Here, we demonstrated that the plasminogen-binding bifidobacterial species B. longum, B. bifidum, B. breve and B. lactis share the key glycolytic enzyme enolase as a surface receptor for human plasminogen. Enolase was visualized on the cell surface of the model strain B. lactis BI07. The His-tagged recombinant protein showed a high affinity for human plasminogen, with an equilibrium dissociation constant in the nanomolar range. By site-directed mutagenesis we demonstrated that the interaction between the B. lactis BI07 enolase and human plasminogen involves an internal plasminogen-binding site homologous to that of pneumococcal enolase. According to our data, the positively charged residues Lys-251 and Lys-255, as well as the negatively charged Glu-252, of the B. lactis BI07 enolase are crucial for plasminogen binding. Acting as a human plasminogen receptor, the bifidobacterial surface enolase is suggested to play an important role in the interaction process with the host., language=, type=