TXN2 Human

Thioredoxin-2 (Trx2) is a member of the thioredoxin family, a group of small multifunctional redox-active proteins. These proteins play crucial roles in various biological processes, including redox signaling, regulation of the mitochondrial membrane potential, and protection against oxidative stress-induced apoptosis .

Thioredoxins are characterized by a conserved active site with a CXXC motif, where two cysteine residues are key to their redox activity . Thioredoxin-2, specifically, is encoded by the TXN2 gene in humans and is primarily located in the mitochondria . The primary function of thioredoxins is to reduce oxidized cysteine residues and cleave disulfide bonds, thereby maintaining cellular redox homeostasis .

The redox activity of thioredoxin-2 involves the reduction of disulfide bonds in substrate proteins. This process begins with the nucleophilic attack by the thiol group of the first cysteine in the active site on the disulfide bond of the substrate. This is followed by the formation of a disulfide bond between the two cysteines in the active site, transferring electrons to the substrate and reducing it . Thioredoxin-2 is then regenerated to its reduced form by thioredoxin reductase in an NADPH-dependent reaction .

Thioredoxin-2 plays a vital role in protecting cells from oxidative damage. It is involved in the regulation of the mitochondrial membrane potential, which is crucial for ATP production and overall cellular energy metabolism . Additionally, thioredoxin-2 helps in mitigating oxidative stress by reducing reactive oxygen species (ROS) levels, thereby preventing apoptosis and promoting cell survival .

Mutations or dysregulation of thioredoxin-2 can have significant implications for human health. Loss-of-function mutations in the TXN2 gene are lethal at the early stages of embryonic development, highlighting the essential role of thioredoxin-2 in cellular function and viability . Moreover, thioredoxin-2 has been implicated in various diseases, including cancer, neurodegenerative disorders, and cardiovascular diseases, due to its role in redox regulation and apoptosis .

Recombinant human thioredoxin-2 is produced using Escherichia coli (E. coli) expression systems. This recombinant protein retains the functional properties of the native protein and is used in various research applications to study its biological functions and potential therapeutic uses .