Characterization of a hemoglobin protease secreted by the pathogenic Escherichia coli strain EB1.
Characterization of a hemoglobin protease secreted by the pathogenic Escherichia coli strain EB1.
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DOI：
10.1084/jem.188.6.1091
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发表时间：
1998-09-21
影响因子：
15.3
通讯作者：
Oudega, B
中科院分区：
文献类型：
--
作者：
Otto, B R;van Dooren, S J;Nuijens, J H;Luirink, J;Oudega, B
许多病原菌可以使用血红素化合物作为铁的来源。致病性大肠杆菌菌株能够利用血红蛋白作为铁源。然而，对于这种微生物，从血红蛋白中获取血红素的机制尚不清楚。我们提出了第一个从人类致病性大肠杆菌血红蛋白蛋白酶（Hbp）的分子特征。大肠杆菌菌株。这种酶似乎也是一种血红素结合蛋白。亲和纯化该双功能蛋白使我们能够鉴定胞外基因产物，并克隆和分析其基因。为Hbp开发的纯化程序使我们能够进行功能研究。该蛋白质与血红蛋白相互作用，降解血红蛋白，随后结合释放的血红素。这些结果表明，该蛋白质参与了这种人类病原体的血红素获取。Hbp属于所谓的IgA 1蛋白酶样蛋白，如其膜转移动力学和DNA序列相似性所示。该蛋白的基因似乎位于仅从人类和动物病原体中分离的大pColV-K30附加体上。这些特征表明Hbp可能是大肠杆菌的一个重要毒力因子，在大肠杆菌的致病过程中起重要作用。大肠杆菌感染。
Many pathogenic bacteria can use heme compounds as a source of iron. Pathogenic Escherichia coli strains are capable of using hemoglobin as an iron source. However, the mechanism of heme acquisition from hemoglobin is not understood for this microorganism. We present the first molecular characterization of a hemoglobin protease (Hbp) from a human pathogenic E. coli strain. The enzyme also appeared to be a heme-binding protein. Affinity purification of this bifunctional protein enabled us to identify the extracellular gene product, and to clone and analyze its gene. A purification procedure developed for Hbp allowed us to perform functional studies. The protein interacted with hemoglobin, degraded it and subsequently bound the released heme. These results suggest that the protein is involved in heme acquisition by this human pathogen. Hbp belongs to the so-called IgA1 protease-like proteins, as indicated by the kinetics of its membrane transfer and DNA sequence similarity. The gene of this protein appears to be located on the large pColV-K30 episome, that only has been isolated from human and animal pathogens. All these characteristics indicate that Hbp may be an important virulence factor that may play a significant role in the pathogenesis of E. coli infections.