New antioxidant with dual functions as a peroxidase and chaperone in Pseudomonas aeruginosa

• Published in: Molecules and cells 2010, 29(2), , pp.145-151
• Main Authors: An, B.C., Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup, Republic of Korea, Lee, S.S., Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup, Republic of Korea, Lee, E.M., Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup, Republic of Korea, Lee, J.T., Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup, Republic of Korea, Wi, S.G., Chonnam National University, Gwangju, Republic of Korea, Jung, H.S., Korea Basic Science Institute, Daejeon, Republic of Korea, Park, W.J., Korea University, Seoul, Republic of Korea, Chung, B.Y., Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup, Republic of Korea
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Antioxidants - chemistry; Antioxidants - metabolism; Biochemistry; Biomedical and Life Sciences; Biomedicine; Biotechnology; Cell Biology; chaperone; Chemical Fractionation; Chromatography, Gel; ESTRES OXIDATIVO; Life Sciences; Models, Biological; Molecular Chaperones - chemistry; Molecular Chaperones - metabolism; Molecular Chaperones - ultrastructure; Molecular Sequence Data; Molecular Weight; OXIDATIVE STRESS; PEROXIDASAS; Peroxidase - chemistry; Peroxidase - metabolism; Peroxidase - ultrastructure; PEROXIDASES; peroxiredoxin; PEROXYDASE; Protein Structure, Quaternary; PSEUDOMONAS AERUGINOSA; Pseudomonas aeruginosa - enzymology; Recombinant Proteins - chemistry; Recombinant Proteins - metabolism; Sequence Alignment; Sequence Homology, Amino Acid; STRESS OXYDATIF; 생물학
• ISSN: 1016-8478; 0219-1032
• DOI: 10.1007/s10059-010-0023-1

Thiol-based peroxiredoxins (Prxs) are conserved throughout all kingdoms. We have found that a conserved typical 2-Cys Prx-like protein (PaPrx) from Pseudomonas aeruginosa bacteria displays diversity in its structure and apparent molecular weight (MW), and can act alternatively as a peroxidase and molecular chaperone. We have also identified a regulatory factor involved in this structural and functional switching. Exposure of P. aeruginosa to hydrogen peroxide (H₂O₂) causes PaPrx to convert from a high MW (HMW) complex to a low MW (LMW) form, which triggers a chaperone to peroxidase functional switch. This structural switching is primarily guided by either the thioredoxin (Trx) or glutathione (GSH) systems. Furthermore, comparison of our structural data [native and non-reducing polyacrylamide gel electrophoresis (PAGE) analysis, size exclusion chromatography (SEC) analysis, and electron microscopy (EM) observations] and enzymatic analyses (peroxidase and chaperone assay) revealed that the formation of oligomeric HMW complex structures increased chaperone activity of PaPrx. These results suggest that multimerization of PaPrx complexes promotes chaperone activity, and dissociation of the complexes into LMW species enhances peroxidase activity. Thus, the dual functions of PaPrx are clearly associated with their ability to form distinct protein structures.