Prolyl3hydroxylase

Prolyl-3-hydroxylase (P3H) refers to a family of enzymes that catalyze the hydroxylation of proline residues within collagen chains. These enzymes are crucial for the proper folding, stability, and function of various collagen types, particularly type I collagen. There are several known isoforms of P3H, each with distinct substrate specificities and cellular localizations. The hydroxylation of proline by P3H occurs at the third carbon position of the proline ring, differentiating it from prolyl-4-hydroxylase which acts at the fourth position.

The P3H enzymes utilize alpha-ketoglutarate, ferrous iron, molecular oxygen, and a 2-oxoglutarate dioxygenase cofactor as substrates. Their activity is essential for the integrity of the extracellular matrix, playing roles in processes such as bone formation, wound healing, and tissue development. Dysregulation of P3H activity has been implicated in various connective tissue disorders and diseases, including osteogenesis imperfecta and certain fibrotic conditions. Research into the specific functions and therapeutic potential of P3H isoforms is ongoing.