α-Enolase binds to human plasminogen on the surface of Bacillus anthracis
α-Enolase binds to human plasminogen on the surface of Bacillus anthracis
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DOI：
10.1016/j.bbapap.2008.03.017
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发表时间：
2008-07-01
影响因子：
3.2
通讯作者：
Bhatnagar, Rakesh
中科院分区：
文献类型：
--
作者：
Agarwal, Shivangi;Kulshreshtha, Parul;Bhatnagar, Rakesh
炭疽芽孢杆菌α烯醇化酶最近被归类为免疫优势抗原和一个有效的毒力因子决定因素。α -烯醇化酶（2-磷酸-D-甘油水解酶，EC 4.2.1.11）是一种关键的糖酵解金属酶，可催化D-(+)-2-磷酸甘油酸脱水生成磷酸烯醇丙酮酸。表面结合的α -烯醇化酶与纤溶酶原的相互作用与组织侵袭有关。在大肠杆菌中表达了炭疽芽孢杆菌α -烯醇化酶，重组酶的纯度达到均匀性，磷酸烯醇丙酮酸的K-m为3.3 mM， V-max为0.506 μ Mmin(-1) mg（-1）。用抗烯醇化酶抗体探测炭疽杆菌全细胞和膜囊泡，证实α -烯醇化酶的表面定位。a -烯醇化酶与人纤溶酶原（而不是纤溶酶）的特异性相互作用从ELISA中可以看出，并且在天然凝胶中的阻滞增强了它在纤溶酶原结合中的作用。在炭疽芽胞杆菌中除烯醇化酶外，还观察到可能存在的纤溶酶原受体。这种结合被发现是羧基肽酶敏感的，暗示了c端赖氨酸残基的作用。重组烯醇化酶在体外显示了层粘连蛋白的结合，这是一种重要的哺乳动物细胞外基质蛋白。纤溶酶原相互作用赋予炭疽芽胞杆菌体外降解纤维连接蛋白和表现纤溶表型的潜力。因此，凭借其与宿主纤溶酶原和细胞外基质蛋白的相互作用，α -烯醇化酶可能有助于增强炭疽芽胞杆菌的侵袭潜力。(C) 2008 Elsevier B.V.版权所有
alpha-enolase of Bacillus anthracis has recently been classified as an immunodominant antigen and a potent virulence factor determinant. alpha-enolase (2-phospho-D-glycerate hydrolase (EC 4.2.1.11), a key glycolytic metalloenzyme catalyzes the dehydration of D-(+)-2-phosphoglyceric acid to phosphoenolpyruvate. Interaction of surface bound alpha-enolase with plasminogen has been incriminated in tissue invasion for pathogenesis. B. anthracis alpha-enolase was expressed in Escherichia coli and the recombinant enzyme was purified to homogeneity that exhibited a K-m of 3.3 mM for phosphoenolpyruvate and a V-max of 0.506 mu Mmin(-1) mg(-1). B. anthracis whole cells and membrane vesicles probed with anti-enolase antibodies confirmed the surface localization of alpha-enolase. The specific interaction of a.-enolase with human plasminogen (but not plasmin) evident from ELISA and the retardation in the native gel reinforced its role in plasminogen binding. Putative plasminogen receptors in B. anthracis other than enolase were also observed. This binding was found to be carboxypeptidase sensitive implicating the role of C-terminal lysine residues. The recombinant enolase displayed in vitro laminin binding, an important mammalian extracellular matrix protein. Plasminogen interaction conferred B. anthracis with a potential to in vitro degrade fibronectin and exhibit fibrinolytic phenotype. Therefore, by virtue of its interaction to host plasminogen and extracellular matrix proteins, alpha-enolase may contribute in augmenting the invasive potential of B. anthracis. (C) 2008 Elsevier B.V. All rights reserved.