Kooi C, Subsin B, Chen R, Pohorelic B, Sokol P A
Department of Microbiology and Infectious Diseases, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada, USA.
Infect Immun. 2006 Jul;74(7):4083-93. doi: 10.1128/IAI.00297-06.
In previous studies we characterized the Burkholderia cenocepacia ZmpA zinc metalloprotease. In this study, we determined that B. cenocepacia has an additional metalloprotease, which we designated ZmpB. The zmpB gene is present in the same species as zmpA and was detected in B. cepacia, B. cenocepacia, B. stabilis, B. ambifaria, and B. pyrrocinia but was absent from B. multivorans, B. vietnamiensis, B. dolosa, and B. anthina. The zmpB gene was expressed, and ZmpB was purified from Escherichia coli by using the pPROEXHTa His(6) Tag expression system. ZmpB has a predicted preproenzyme structure typical of thermolysin-like proteases and is distantly related to Bacillus cereus bacillolysin. ZmpB was expressed as a 63-kDa preproenzyme precursor that was autocatalytically cleaved into mature ZmpB (35 kDa) and a 27-kDa prepropeptide. EDTA, 1,10-phenanthroline, and Zn(2+) cations inhibited ZmpB enzyme activity, indicating that it is a metalloprotease. ZmpB had proteolytic activity against alpha-1 proteinase inhibitor, alpha(2)-macrogobulin, type IV collagen, fibronectin, lactoferrin, transferrin, and immunoglobulins. B. cenocepacia zmpB and zmpA zmpB mutants had no proteolytic activity against casein and were less virulent in a rat agar bead chronic infection model, indicating that zmpB is involved in B. cenocepacia virulence. Expression of zmpB was regulated by both the CepIR and CciIR quorum-sensing systems.
在之前的研究中，我们对洋葱伯克霍尔德菌ZmpA锌金属蛋白酶进行了特性描述。在本研究中，我们确定洋葱伯克霍尔德菌还有另一种金属蛋白酶，我们将其命名为ZmpB。zmpB基因与zmpA存在于同一物种中，在洋葱伯克霍尔德菌、洋葱伯克霍尔德菌、稳定伯克霍尔德菌、多 ambifaria伯克霍尔德菌和pyrrocinia伯克霍尔德菌中被检测到，但在多食伯克霍尔德菌、越南伯克霍尔德菌、多洛萨伯克霍尔德菌和anthina伯克霍尔德菌中未检测到。zmpB基因被表达，并且通过使用pPROEXHTa His(6)标签表达系统从大肠杆菌中纯化出ZmpB。ZmpB具有预测的前原酶结构，这是嗜热菌蛋白酶样蛋白酶的典型结构，并且与蜡样芽孢杆菌芽孢溶素关系较远。ZmpB以63 kDa的前原酶前体形式表达，该前体自动催化裂解为成熟的ZmpB（35 kDa）和27 kDa的前肽。EDTA、1,10 - 菲咯啉和Zn(2+)阳离子抑制ZmpB酶活性，表明它是一种金属蛋白酶。ZmpB对α-1蛋白酶抑制剂、α(2)-巨球蛋白、IV型胶原、纤连蛋白、乳铁蛋白、转铁蛋白和免疫球蛋白具有蛋白水解活性。洋葱伯克霍尔德菌zmpB和zmpA zmpB突变体对酪蛋白没有蛋白水解活性，并且在大鼠琼脂珠慢性感染模型中致病性较低，表明zmpB参与了洋葱伯克霍尔德菌的致病性。zmpB的表达受群体感应系统CepIR和CciIR的调控。
