Figure 3.

Functional switch of identified Helicobacter pylori biomarkers in response to environmental stresses. Alkylhydroperoxide reductase (AhpC), neutrophil-activating protein (NapA) and non-heme iron-binding ferritin (Pfr) are identified by clinical proteomics as potential biomarkers under different environmental stresses. Further biochemical characterization showed the protein structure change was accompanied by functional switch of these proteins under varied environmental conditions, such as oxidative, acid and osmotic stresses[34,36,38]. The PDB ID of Helicobacter pylori (H. pylori) AhpC, NapA and Pfr are 1ZOF[61], 1JI4[62] and 3EGM[63], respectively.