peptidyl-proline dioxygenase activity

Definition

Target type: molecularfunction

Catalysis of the reaction: peptidyl L-proline + 2-oxoglutarate + O2 = peptidyl hydroxy-L-proline + succinate + CO2. [GOC:mah, GOC:vw, PMID:24550447, PMID:24550462]

Peptidyl-proline dioxygenase (PPO) activity is a crucial enzymatic function involved in the post-translational modification of proteins. This activity catalyzes the hydroxylation of proline residues within proteins, specifically at the *trans* position relative to the peptide bond. This hydroxylation reaction requires molecular oxygen (O2), a reducing agent (typically ascorbate), and ferrous iron (Fe2+) as cofactors. The reaction mechanism proceeds through a series of steps, starting with the binding of both the proline-containing peptide substrate and molecular oxygen to the enzyme. The Fe2+ ion in the enzyme's active site then facilitates the activation of oxygen, leading to the formation of a reactive oxygen species. This activated oxygen attacks the proline residue, leading to the insertion of a hydroxyl group (-OH) at the *trans*-position of the proline ring. This hydroxylation reaction results in the formation of a 4-hydroxyproline residue within the protein. PPO activity plays a significant role in various biological processes, including collagen biosynthesis, cell signaling, and regulation of protein stability. In collagen biosynthesis, PPO enzymes catalyze the hydroxylation of specific proline residues in procollagen chains, which is essential for the proper folding and assembly of collagen fibrils. These fibrils provide structural support to tissues throughout the body. In cell signaling, PPO enzymes have been implicated in the regulation of signaling pathways by modifying the activity of signaling proteins. Additionally, PPO activity can influence protein stability by affecting the folding and conformation of proteins. The hydroxylation of proline residues can enhance protein stability by influencing protein-protein interactions and by protecting proteins from proteolytic degradation. Overall, peptidyl-proline dioxygenase activity is a fundamental enzymatic process that contributes to the modification and function of a wide range of proteins, playing a critical role in maintaining cellular function and tissue integrity.'
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Proteins (2)

Compounds (21)