School of Molecular Bioscience, The University of Sydney, Sydney, Australia.
Proteomics. 2011 Aug;11(15):3056-69. doi: 10.1002/pmic.201000807. Epub 2011 Jun 14.
Pseudomonas aeruginosa is a ubiquitous pathogen most typically associated with wound infections, but also the main cause of mortality in patients suffering from cystic fibrosis (CF). The ability to adapt to oxidative stress associated with host immune defense may be one mechanism by which P. aeruginosa establishes infection in the cystic fibrosis lung and eventually out-competes other pathogenic bacteria to persist into chronic infection. We utilized a proteomics approach to identify the proteins associated with the oxidative stress response of P. aeruginosa PAO1 to hydrogen peroxide and superoxide-inducing paraquat. 2-DE and MS allowed for the identification of 59 and 58 protein spots that were statistically significantly altered following H(2) O(2) and paraquat treatment, respectively. We observed a unique mass and pI pattern for alkylhydroperoxide reductase C (AhpC) that was replicated by hypothetical protein PA3529 following treatment with 10 mM H(2) O(2) . AhpC belongs to the 2-Cys peroxiredoxin family and is a redox enzyme responsible for removing peroxides in bacterial cells. MS analysis showed that PA3529 was altered by the formation of a dimer via a disulfide bond in a manner analogous to that known for AhpC, and by cysteine overoxidation to Cys-sulfonic acid (SO(3) H) postoxidative stress. PA3529 is therefore a functional AhpC paralog expressed under H(2) O(2) stress. Following paraquat-induced oxidative stress, we also observed the overabundance and likely oxidative modification of a second hypothetical antioxidant protein (PA3450) that shares sequence similarity with 1-Cys peroxiredoxins. Other induced proteins included known oxidative stress proteins (superoxide dismutase and catalase), as well as those involved in iron acquisition (siderophore biosynthesis and receptor proteins FpvA and FptA) and hypothetical proteins, including others predicted to be antioxidants (PA0848). These data suggest that P. aeruginosa contains a plethora of novel antioxidant proteins that contribute to its increased resistance against oxidative stress.
铜绿假单胞菌是一种普遍存在的病原体，最常与伤口感染有关，但也是囊性纤维化（CF）患者死亡的主要原因。适应与宿主免疫防御相关的氧化应激可能是铜绿假单胞菌在囊性纤维化肺部建立感染并最终击败其他病原菌而持续慢性感染的机制之一。我们利用蛋白质组学方法来鉴定铜绿假单胞菌 PAO1 与过氧化氢和诱导过氧化物的对苯二醌相关的氧化应激反应的蛋白质。2-DE 和 MS 分别允许鉴定 59 和 58 个蛋白斑点，它们在 H 2 O 2 和对苯二醌处理后统计学上发生显著变化。我们观察到烷基氢过氧化物还原酶 C（AhpC）的独特质量和 pI 模式，在 10 mM H 2 O 2 处理后，通过假设蛋白 PA3529 得到复制。AhpC 属于 2-Cys 过氧化物酶家族，是一种在细菌细胞中去除过氧化物的氧化还原酶。MS 分析表明，PA3529 通过形成二聚体发生变化，通过二硫键类似于 AhpC 已知的方式，并且在氧化应激后通过半胱氨酸过氧化形成 Cys-磺酸（SO 3 H）。因此，PA3529 是一种在 H 2 O 2 应激下表达的功能性 AhpC 旁系同源物。在对苯二醌诱导的氧化应激后，我们还观察到第二种假设抗氧化蛋白（PA3450）的过度表达和可能的氧化修饰，该蛋白与 1-Cys 过氧化物酶具有序列相似性。其他诱导的蛋白质包括已知的氧化应激蛋白（超氧化物歧化酶和过氧化氢酶），以及参与铁摄取的蛋白质（铁载体生物合成和受体蛋白 FpvA 和 FptA）和假设蛋白，包括其他预测为抗氧化剂的蛋白（PA0848）。这些数据表明，铜绿假单胞菌含有大量新的抗氧化蛋白，有助于其对氧化应激的抵抗力增加。
