@article{mbs:/content/journal/micro/10.1099/mic.0.028795-0, author = "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", title = "Bifidobacterial enolase, a cell surface receptor for human plasminogen involved in the interaction with the host", journal= "Microbiology", year = "2009", volume = "155", number = "10", pages = "3294-3303", doi = "https://doi.org/10.1099/mic.0.028795-0", url = "https://www.microbiologyresearch.org/content/journal/micro/10.1099/mic.0.028795-0", publisher = "Microbiology Society", issn = "1465-2080", type = "Journal Article", keywords = "PEP, phosphoenolpyruvate", keywords = "Plg, plasminogen", keywords = "2-PGE, 2-phosphoglycerate", keywords = "EACA, ϵ-aminocaproic acid", 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.", }