BINDING OF HUMAN PLASMINOGEN TO BORRELIA-BURGDORFERI
BINDING OF HUMAN PLASMINOGEN TO BORRELIA-BURGDORFERI
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DOI：
10.1128/iai.63.9.3491-3496.1995
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发表时间：
1995-09-01
影响因子：
3.1
通讯作者：
KLEMPNER, MS
中科院分区：
文献类型：
--
作者：
HU, LT;PERIDES, G;KLEMPNER, MS
我们研究了纤溶酶原与伯氏疏螺旋体的结合，伯氏疏螺旋体是一种引起莱姆病的螺旋体，它不产生内源性蛋白酶来消化细胞外基质蛋白。使用i -125标记的纤溶酶原，我们证明了伯氏疏螺旋体与人纤溶酶原结合，并且这种结合被未标记的纤溶酶原抑制。i -125标记的纤溶酶原与伯氏疏螺旋体的结合也被赖氨酸类似物e -氨基己酸所抑制。Glu-或lys -纤溶酶原与B， burgdorferi的结合无显著差异，在B， burgdorferi低传代（感染性）和高传代（非感染性）分离株中，纤溶酶原的结合相似。结合在伯氏疏螺旋体表面的纤溶酶原可以通过人尿激酶型纤溶酶原激活剂转化为纤溶酶，i -125标记的纤溶酶原配体斑点显示有两个显著的结合蛋白，分别为70和30 kDa。Western blot（免疫印迹）检测到30 kda蛋白为伯氏疏螺旋体外表面蛋白A （Osp A）。i -125标记的纤溶酶原与70 kda蛋白和Osp A的结合被抑制了90%，未标记的纤溶酶原过量了1000倍。通过扫描密度测定，70-kDa带结合的i -125标记的纤溶酶原比Osp A多10倍，Osp A缺陷突变体和野生型B，伯氏疏螺旋体结合相同数量的i -125标记的纤溶酶原。Osp a缺陷突变体的膜蛋白配体印迹显示，i -125标记的纤溶酶原仅在70 kda蛋白上存在关联。双向凝胶电泳显示，70 kda蛋白的pi近似于5.3，与Osp a明显分离。宿主纤溶蛋白（原）与borrelial表面蛋白的结合提供了伯氏疏螺旋体消化细胞外基质并传播的机制。
We studied the binding of plasminogen to Borrelia burgdorferi, a spirochete which causes Lyme disease and produces no endogenous proteases which digest extracellular matrix proteins, Using I-125-labeled plasminogen, we demonstrated that B. burgdorferi bound human plasminogen and that this binding was inhibitable with unlabeled plasminogen. I-125-labeled plasminogen binding by B. burgdorferi was also inhibited by the lysine analog E-aminocaproic acid. There was no significant difference in the binding of Glu- or Lys-plasminogen to B, burgdorferi, Binding of plasminogen was similar in low-passage (infectious) and high-passage (noninfectious) isolates of B, burgdorferi. Plasminogen bound to the surface of B. burgdorferi could be converted into plasmin by a human urokinase-type plasminogen activator, I-125-labeled plasminogen ligand blots of borrelial membrane proteins demonstrated two prominent binding proteins at similar to 70 and similar to 30 kDa. By Western blot (immunoblot), the 30-kDa protein was found to be outer surface protein A (Osp A) of B. burgdorferi. I-125-labeled plasminogen binding to both the 70-kDa protein and Osp A was inhibited by similar to 90% with a 1,000-fold excess of unlabeled plasminogen. By scanning densitometry, the 70-kDa band bound >10 time more I-125-labeled plasminogen than did Osp A, An Osp A-deficient mutant of B. burgdorferi and wild-type B, burgdorferi bound equal amounts of I-125-labeled plasminogen. Ligand blots of membrane proteins from an Osp A-deficient mutant showed association of I-125-labeled plasminogen at only the 70-kDa protein. Two-dimensional gel electrophoresis showed that the 70-kDa protein had a pi of similar to 5.3, clearly separable from Osp A. The association of host plasmin(ogen) with borrelial surface proteins provides a mechanism by which B. burgdorferi can digest extracellular matrix and disseminate.