Smith A W, Chahal B, French G L
Department of Microbiology, UMDS Guy's Hospital Medical School, London, UK.
Mol Microbiol. 1994 Jul;13(1):153-60. doi: 10.1111/j.1365-2958.1994.tb00410.x.
The human bacterial pathogen Helicobacter pylori has been suggested to be the causative agent of the most common chronic infection of man. Since its first isolation in 1982, H. pylori has been associated with gastric and duodenal ulcer disease, and more recently, gastric cancer. The proteolytic digestion of gastric mucus by this microorganism has been suggested as an important mechanism by which its pathogenicity is at least partly exerted. Here we report the detection of protease activity in H. pylori total-cell and supernatant extracts. On the basis that zinc metalloproteases are common microbial pathogenicity factors, we identified a single protein in H. pylori protein extracts with antibodies to the Pseudomonas aeruginosa elastase (a secreted zinc metalloprotease). This same protein was identified by pooled serum from patients infected with H. pylori. We used the functional and immunological relationship between the P. aeruginosa elastase and the Vibrio cholerae haemagglutinin/protease (HAP) to clone the H. pylori hap gene, which was over 99% similar to the V. cholerae hap gene in the coding region. A 4 kb DNA fragment containing the entire cloned gene was highly unstable in Escherichia coli and Bacillus subtilis cloning vectors. We also demonstrated that a hap-like gene sequence is present in all nine Helicobacter species so far discovered. The V. cholerae HAP was first classified on the basis of its mucinase activity.
人类细菌病原体幽门螺杆菌被认为是人类最常见慢性感染的病原体。自1982年首次分离出幽门螺杆菌以来，它一直与胃溃疡和十二指肠溃疡疾病相关，最近还与胃癌有关。这种微生物对胃黏液的蛋白水解作用被认为是其致病性至少部分得以发挥的重要机制。在此，我们报告了在幽门螺杆菌全细胞提取物和上清液提取物中检测到蛋白酶活性。基于锌金属蛋白酶是常见的微生物致病因子这一观点，我们用抗铜绿假单胞菌弹性蛋白酶（一种分泌型锌金属蛋白酶）的抗体在幽门螺杆菌蛋白提取物中鉴定出一种单一蛋白质。感染幽门螺杆菌患者的混合血清也鉴定出了同一种蛋白质。我们利用铜绿假单胞菌弹性蛋白酶与霍乱弧菌血凝素/蛋白酶（HAP）之间的功能和免疫关系克隆了幽门螺杆菌hap基因，该基因在编码区与霍乱弧菌hap基因的相似度超过99%。包含整个克隆基因的4 kb DNA片段在大肠杆菌和枯草芽孢杆菌克隆载体中高度不稳定。我们还证明，到目前为止发现的所有9种幽门螺杆菌中都存在一个类似hap的基因序列。霍乱弧菌HAP最初是根据其黏蛋白酶活性进行分类的。
