"Thiol-specific peroxidase that catalyzes the reduction of"

"Belongs to the peroxiredoxin family. AhpC/Prx1 subfamily"

"PpPrx suppressed the thermal aggregation of the model substrate MDH at 43°C in a concentration-dependent manner (Fig.2B). At a subunit molar ratio of PpPrx to MDH of 0.5 vs. 1, MDH aggregation was completely suppressed. PpPrx can also efficiently protect the thermal aggregation of CS (Fig.2C), suggesting that PpPrx can indeed act as an efficient molecular chaperone. However, foldase activity as another chaperone activity was not detected (data not shown)."

"PpPrx exhibited low H2O2catabolic peroxidase activity (Fig.2D), substantially lower than that of yeast Trx-dependent Prx (yTPx), but PpPrx exhibited five times higher the chaperone activity than yTPx, used as a positive control."

"The HMW complex fraction (F-1) exhibited high chaperone activity about fivefold compare to LMW fraction (F-2) and total protein fraction (Fig.3E), indicating that the chaperone activity of PpPrx was significantly affected by the structural composition. In contrast, the F-2 fraction had more peroxidase activity than the total protein, and the F-1 fraction showed lower peroxidase activity than total protein (Fig.3F)."

"PpPrx and PaPrx can alternatively function as a peroxidase and chaperone."

"PpPrx predominates with a high molecular weight (HMW) complex and chaperone activity, whereas PaPrx has mainly low molecular weight (LMW) structures and peroxidase activity."

"locus **PP_1084** encodes a cytosolic **AhpC/Prx1-family (typical 2-Cys) peroxiredoxin**, experimentally characterized as a **thioredoxin-dependent peroxidase** that can also act as a **stress-responsive molecular chaperone** via oligomerization-dependent functional switching"

"The best-supported primary substrate in KT2440 experiments is **H2O2**, with broader substrate scope (e.g., organic hydroperoxides, peroxynitrite) supported by strong family-level evidence for typical 2-Cys peroxiredoxins"

"identifying it as a **21 kDa AhpC/Tsa family peroxiredoxin** (typical 2-Cys), which aligns with the UniProt description and subfamily assignment"

"enriched in **high-molecular-weight (HMW)** oligomeric complexes, demonstrated by suppression of thermal aggregation of model substrates (e.g., malate dehydrogenase), consistent with a"

"PSORTb-based prediction placed PP1084/PpPrx in the **cytoplasm**, aligning with expected localization for a thioredoxin-coupled peroxide detox enzyme operating on intracellular peroxides and protein thiol redox balance"

"PP1084/PpPrx was discovered among **disulfide-bonded proteins** enriched after **oxidative treatments (H2O2, gamma rays)** in KT2440, consistent with involvement in oxidative-stress response and thiol redox homeostasis"

"Exposure to **H2O2** drives structural changes and a corresponding functional switch, and the thioredoxin system is described as a primary guide of this switching behavior"

"PP_1084/PpPrx self-associates into high-molecular-weight (HMW) complexes and lower-molecular-weight (LMW) species"