Interaction between 1-Cys peroxiredoxin and ascorbate in the response to H₂O₂ exposure in Pseudomonas aeruginosa

Author(s)

Aleixo-Silva, Rogerio L. ; Domingos, Renato M. ; Trujillo, Madia ; Gomes, Fernando ; Machado, Luciene O. ; Oliveira, Cristiano L. P. ; Baldini, Regina ; Netto, Luis E. S.

• Document type: Journal article
• Source: REDOX BIOLOGY; v. 84, p. 12-pg., 2025-07-01.

Abstract

Pseudomonas aeruginosa, a leading cause of hospital-acquired infections, triggers host defenses, including oxidant release by phagocytes. Targeting bacterial antioxidants could reduce pathogen infectivity. This study investigates LsfA, a 1-Cys peroxiredoxin (Prx), member of the Prx6 subfamily, involved in P. aeruginosa virulence. LsfA efficiently reduced various peroxides (10(6)-10(7) M(-1)s(-1)), while exhibiting hyperoxidation resistance (k(hyperoxidation) similar to 10(2) M(-1)s(-1)). Despite its substrate oxidizing promiscuity, LsfA displayed specific reduction by ascorbate (2.2 x 10(3) M(-1)s(-1)). Moreover, elucidating the LsfA's crystallographic structures in the reduced and sulfinic/sulfonic acid states at 2.4 and 2.0 & Aring; resolutions unveiled possible residues related to ascorbate binding. Small-angle X-ray scattering (SAXS) and size-exclusion chromatography (SEC) confirmed LsfA as a dimer regardless of its oxidative state. Microbiological assays, including a real-time analysis employing Hyper7, a genetically encoded probe, showed that ascorbate enhanced H2O2 removal in a LsfA-dependent manner. Hence, our integrated structural, biochemical, and microbiological analyses underscored the significance of the ascorbate-LsfA pathway in P. aeruginosa response to H2O2. (AU)

• FAPESP's process: 20/00845-4 - Unraveling the biological role of LsfA, a 1-Cys Prx involved in the P. aeruginosa virulence
• Grantee: Rogério Luis Aleixo Silva
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 13/07937-8 - Redoxome - Redox Processes in Biomedicine
• Grantee: Ohara Augusto
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC