Peroxiredoxinsystemen

Peroxiredoxinsystemen, commonly known as peroxiredoxins (Prx), are a family of highly conserved cysteine-based antioxidant enzymes found in all organisms from bacteria to humans. Their primary function is to reduce a variety of reactive oxygen species (ROS), such as hydrogen peroxide and organic hydroperoxides, thus protecting cells from oxidative damage. This protective role is crucial for maintaining cellular homeostasis and preventing the development of various diseases linked to oxidative stress, including cancer, neurodegenerative disorders, and aging.

The catalytic mechanism of peroxiredoxins involves a specific cysteine residue in their active site. This cysteine undergoes oxidation by ROS, forming a sulfenic acid intermediate. This intermediate can then be reduced by another molecule of ROS or by a reducing agent like thioredoxin, regenerating the active enzyme and completing the catalytic cycle. Different subclasses of peroxiredoxins exist, such as 1-Cys, 2-Cys, and 7-Cys Prx, each with variations in their active site and substrate specificity.

Beyond their direct antioxidant activity, peroxiredoxins are increasingly recognized for their involvement in various cellular signaling pathways. They can act as sensors and integrators of oxidative stress, influencing processes such as cell proliferation, differentiation, and apoptosis. Their ability to modulate the levels of ROS, which are also important signaling molecules, underscores their multifaceted roles in cellular physiology and pathophysiology.