Identification of differentially regulated proteins in metronidozole resistant Helicobacter pylori by proteome techniques
Identification of differentially regulated proteins in metronidozole resistant Helicobacter pylori by proteome techniques
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DOI：
10.1002/1615-9861(200104)1:4
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发表时间：
2001-04
期刊：
影响因子：
3.4
通讯作者：
C. McAtee;P. Hoffman;D. Berg
中科院分区：
文献类型：
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作者：
C. McAtee;P. Hoffman;D. Berg
对甲硝唑 (MTZ) 的耐药性在许多社会的幽门螺杆菌菌株中很常见，这是由于一种或多种细胞硝基还原酶基因功能缺失突变造成的。当发挥作用时，这些酶将 MTZ 从无害的前药转化为诱变和杀菌产品（可能是羟胺型化合物），并在此过程中可能产生活性活性氧代谢物。在这里，我们检查了菌株 26695 的一种衍生物的蛋白质谱，该菌株对中等水平的 MTZ 具有抗性，因为 rdxA (HP0954) 发生突变，rdxA (HP0954) 是这些硝基还原酶中最重要的基因。该菌株在有或没有 18 μg/mL MTZ 的情况下生长，以评估亚致死暴露是否会触发适应性反应。对细菌裂解物进行二维 (2-D) 电泳，并通过质谱和序列分析鉴定蛋白质条带。在使用 MTZ 生长期间，几种蛋白质至少减少两倍，但烷基氢过氧化物还原酶 (AHP)（由 ahpC HP1563 编码）的各种同工型的水平却有所增加。 AHP 是一种必需酶，与各种原核和真核系统中的氧毒性抵抗力有关；我们认为，rdxA 突变菌株在暴露于 MTZ 期间增加 AHP 丰度的能力对于实现抗性表型至关重要。更一般地说，这些结果凸显了蛋白质组分析的潜力，可以追踪病原菌如何应对治疗或宿主对感染的反应所带来的挑战。
Resistance to metronidazole (MTZ) is common among Helicobacter pylori strains in many societies, and results from loss of function mutations in genes for one or more cellular nitroreductases. When functional, these enzymes convert MTZ from a harmless prodrug to mutagenic and bacteriocidal products (probably hydroxylamine‐type compounds), and in the process may generate active reactive oxygen metabolites. Here we examine the protein profiles of a derivative of strain 26695 that is resistant to moderate levels of MTZ because of mutation in rdxA (HP0954), the gene for the most important of these nitroreductases. The strain was grown with and without 18 μg/mL of MTZ to assess whether sublethal exposure triggers an adaptive response. Bacterial lysates were subjected to two‐dimensional (2‐D) electrophoresis and protein bands were identified by mass spectrometry and sequence analysis. Several proteins were decreased at least two‐fold during growth with MTZ, yet the levels of various isoforms of alkylhydroperoxide reductase (AHP) (encoded by ahpC HP1563) were increased. AHP is an essential enzyme, and had been linked to resistance to oxygen toxicity in various prokaryotic and eukaryotic systems; we propose that the ability of an rdxA mutant strain to increase AHP abundance during exposure to MTZ is critically important in the realization of the resistance phenotype. More generally, these results highlight the potential of proteome analysis to tracing out how pathogenic bacteria cope with the challenges imposed on them by therapy or host responses to infection.