title: The changes of proteomes components of Helicobacter pylori in response to acid stress without urea.
abstract: Acid stress is the most obvious challenge Helicobacter pylori encounters in human stomach. The urease system is the basic process used to maintain periplasmic and cytoplasmic pH near neutrality when H. pylori is exposed to acidic condition. However, since the urea concentration in gastric juice is approximately 1 mM, considered possibly insufficient to ensure the survival of H. pylori, it is postulated that additional mechanisms of pH homeostasis may contribute to the acid adaptation in H. pylori. In order to identify the acid-related proteins other than the urease system we have compared the proteome profiles of H. pylori strain 26695 exposed to different levels of external pH (7.4, 6.0, 5.0, 4.0, 3.0, and 2.0) for 30 min in the absence of urea using 2-DE. Differentially expressed proteins were identified by MALDI-TOF-TOF-MS analysis, which turned out to be 36 different proteins. The functions of these proteins included ammonia production, molecular chaperones, energy metabolism, cell envelope, response regulator and some proteins with unknown function. SOM analysis indicated that H. pylori responds to acid stress through multi-mechanisms involving many proteins, which depend on the levels of acidity the cells encounter.
authors.affiliation: Department of Microbiology, School of Medicine, Shandong University, Jinan, PR China.
authors.forename: Chunhong
authors.initials: C
authors.lastname: Shao
authors.forename: Qunye
authors.initials: Q
authors.lastname: Zhang
authors.forename: Wei
authors.initials: W
authors.lastname: Tang
authors.forename: Wei
authors.initials: W
authors.lastname: Qu
authors.forename: Yabin
authors.initials: Y
authors.lastname: Zhou
authors.forename: Yundong
authors.initials: Y
authors.lastname: Sun
authors.forename: Han
authors.initials: H
authors.lastname: Yu
authors.forename: Jihui
authors.initials: J
authors.lastname: Jia
mesh_terms: D000143:Acids / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015180:Electrophoresis, Gel, Two-Dimensional; D016481:Helicobacter Infections / Q000382:microbiology*; D016480:Helicobacter pylori / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008954:Models, Biological; D020543:Proteome / Q000235:genetics / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014508:Urea / Q000378:metabolism*
chemical_list: D000143:Acids; D001426:Bacterial Proteins; D020543:Proteome; D014508:Urea