Escherichia coli outer membrane protease OmpT confers resistance to urinary cationic peptides
Escherichia coli outer membrane protease OmpT confers resistance to urinary cationic peptides
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大肠杆菌外膜蛋白酶 OmpT 赋予尿阳离子肽抗性
DOI：
10.1111/j.1348-0421.2010.00238.x
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发表时间：
2010-08-01
影响因子：
2.6
通讯作者：
Huang, Sheng-He
中科院分区：
文献类型：
--
作者：
Hui, Chang-Ye;Guo, Yan;Huang, Sheng-He
位于外膜的大肠杆菌OmpT已被表征为纤溶酶原激活剂，具有水解鱼精蛋白并阻止其进入的能力。本研究采用膜超滤和弱阳离子交换色谱相结合的方法从人尿中纯化了一个低分子量阳离子肽复合物。通过检测OmpT敲除菌株，研究OmpT对大肠杆菌尿阳离子肽耐药性的影响。ompT突变体比ompT+菌株对尿阳离子肽更敏感，这种差异通过与携带ompT基因的pUC19互补而消除。尿蛋白酶抑制剂乌司他丁可显著降低ompT+菌株的耐药性。总的来说，数据表明OmpT可能通过使大肠杆菌抵抗尿阳离子肽的抗菌活性来帮助大肠杆菌在尿路中存活更长时间。
Escherichia coli OmpT, located in the outer membrane, has been characterized as a plasminogen activator, with the ability to hydrolyze protamine and block its entry. In this investigation, a complex of low molecular weight cationic peptides purified from human urine by a combination of membrane ultrafiltration and weak cation exchange chromatography was characterized. The impact of OmpT on E. coli resistance to urinary cationic peptides was investigated by testing ompT knockout strains. The ompT mutants were more susceptible to urinary cationic peptides than ompT+ strains, and this difference was abolished by complementation of the mutants with pUC19 carrying the ompT gene. The urinary protease inhibitor ulinastatin greatly decreased the resistance of the ompT+ strains. Overall, the data indicate that OmpT may help E. coli persist longer in the urinary tract by enabling it to resist the antimicrobial activity of urinary cationic peptides.