Bifidobacterial enolase, a cell surface receptor for human plasminogen involved in the interaction with the host
Bifidobacterial enolase, a cell surface receptor for human plasminogen involved in the interaction with the host
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DOI：
10.1099/mic.0.028795-0
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发表时间：
2009-10-01
期刊：
影响因子：
2.8
通讯作者：
Brigidi, Patrizia
中科院分区：
文献类型：
--
作者：
Candela, Marco;Biagi, Elena;Brigidi, Patrizia
与宿主纤溶酶原/纤溶酶系统的相互作用是双歧杆菌与人类宿主分子串扰的一个新组成部分。在这里，我们证明了结合纤溶酶原的双歧杆菌长双歧杆菌、两歧双歧杆菌、短双歧杆菌和乳酸双歧杆菌共享关键的糖酵解酶烯醇化酶，作为人类纤溶酶原的表面受体。模型菌株B. laactis BI07细胞表面可见烯醇化酶。his标记的重组蛋白对人纤溶酶原具有高亲和力，其平衡解离常数在纳摩尔范围内。通过定点诱变，我们证实乳酸杆菌BI07烯醇化酶与人纤溶酶原之间的相互作用涉及一个与肺炎球菌烯醇化酶同源的内部纤溶酶原结合位点。根据我们的数据，B. lactis BI07烯醇化酶的带正电荷残基Lys-251和Lys-255以及带负电荷的Glu-252对纤溶酶原的结合至关重要。双歧杆菌表面烯醇化酶作为人纤溶酶原受体，在与宿主的相互作用过程中发挥重要作用。
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.