protein-disulfide reductase activity

Definition

Target type: molecularfunction

Catalysis of the reaction: a protein with reduced sulfide groups = a protein with oxidized disulfide bonds. [PMID:7559385]

Protein-disulfide reductase activity is a catalytic function that reduces disulfide bonds in proteins, a process crucial for protein folding and function. Disulfide bonds are covalent links between two cysteine residues within a protein, contributing to its tertiary and quaternary structures. These bonds are essential for the stability and function of many proteins, particularly those secreted into the extracellular environment or residing in oxidizing cellular compartments.

Disulfide reductase enzymes employ a variety of mechanisms to catalyze disulfide bond reduction, typically using electrons donated by reducing agents such as NADH or NADPH. A common strategy involves the formation of a thiolate-disulfide intermediate, where the enzyme's active site cysteine residue interacts with the protein disulfide bond. This intermediate facilitates electron transfer, leading to the reduction of the disulfide bond and the regeneration of the enzyme's active site.

Protein-disulfide reductases play critical roles in diverse cellular processes, including:

* **Protein folding:** They facilitate the proper formation of disulfide bonds during protein synthesis and folding, ensuring the correct tertiary structure of proteins.
* **Redox regulation:** They participate in cellular redox homeostasis by maintaining the balance of reduced and oxidized proteins, contributing to signaling pathways and stress response.
* **Secretion and trafficking:** They aid in the transport and localization of proteins within cells, particularly for proteins destined for the extracellular environment.
* **Antioxidant defense:** They protect cells from oxidative damage by reducing disulfide bonds in proteins that have become oxidized due to reactive oxygen species.

Disulfide reductase activity is essential for the function of a vast array of proteins and cellular processes. Defects in these enzymes can lead to a range of diseases, highlighting their crucial role in human health.'
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Proteins (5)

Compounds (6)