Lab. Desenvolvimento de Vacinas, Instituto Butantan, São Paulo, Brazil.
Programa de Pós-Graduação Interunidades em Biotecnologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil.
Med Microbiol Immunol. 2020 Apr;209(2):201-213. doi: 10.1007/s00430-020-00664-4. Epub 2020 Feb 20.
Leptospirosis is a worldwide spread zoonosis, caused by pathogenic Leptospira. Evidences suggest that compromised hemostasis might be involved in the leptospirosis pathophysiology. In the genome of L. interrogans serovar Copenhageni, we found two genes coding for proteins which comprise von Willebrand factor (VWF) A domains (BatA and BatB). As VWF A domains exhibit multiple binding sites which contributes to human VWF hemostatic functions, we hypothesized that the L. interrogans BatA and BatB proteins could be involved in the hemostatic impairment during leptospirosis. We have cloned, expressed in Escherichia coli, and purified recombinant BatA and BatB. The influence of recombinant BatA and BatB on different in vitro hemostatic assays evaluating the enzymatic activity, platelet aggregation and fibrinogen integrity was investigated. We describe BatB as a new serine protease which is able to cleave thrombin chromogenic substrate, fibrin, fibrinogen, gelatin and casein; while BatA is active only towards fibrinogen. BatA and BatB interfere with the platelet aggregation induced by VWF/ristocetin and thrombin. Our results suggest an important role of the L. interrogans serovar Copenhageni Bat proteins in the hemostasis dysfunction observed during leptospirosis and contribute to the understanding of the leptospirosis pathophysiological mechanisms.
钩端螺旋体病是一种世界性分布的动物源性传染病，由致病性钩端螺旋体引起。有证据表明，止血功能受损可能与钩端螺旋体病的病理生理学有关。在钩端螺旋体血清群哥本哈根菌的基因组中，我们发现了两个编码包含血管性血友病因子（VWF）A 结构域的蛋白的基因（BatA 和 BatB）。由于 VWF A 结构域具有多个结合位点，这些结合位点有助于人类 VWF 的止血功能，我们假设钩端螺旋体血清群哥本哈根菌的 BatA 和 BatB 蛋白可能参与了钩端螺旋体病期间的止血功能障碍。我们已经克隆、在大肠杆菌中表达并纯化了重组 BatA 和 BatB。研究了重组 BatA 和 BatB 对不同体外止血测定的影响，这些测定评估了酶活性、血小板聚集和纤维蛋白原完整性。我们将 BatB 描述为一种新的丝氨酸蛋白酶，它能够切割凝血酶发色底物、纤维蛋白、纤维蛋白原、明胶和酪蛋白；而 BatA 仅对纤维蛋白原具有活性。BatA 和 BatB 干扰 VWF/瑞斯托菌素和凝血酶诱导的血小板聚集。我们的结果表明，钩端螺旋体血清群哥本哈根菌 Bat 蛋白在钩端螺旋体病期间观察到的止血功能障碍中起重要作用，并有助于理解钩端螺旋体病的病理生理学机制。
