nounIntermediate
Definition
Modified amino acid (Hyp, O) found almost exclusively in collagen, where it stabilizes the triple-helix structure through stereoelectronic effects and water-bridged hydrogen bonds.

Detailed Explanation

Modified amino acid (Hyp, O) found almost exclusively in collagen, where it stabilizes the triple-helix structure through stereoelectronic effects and water-bridged hydrogen bonds. Formed by post-translational hydroxylation of proline by prolyl hydroxylase, an enzyme that absolutely requires vitamin C (ascorbic acid) as a cofactor. Vitamin C deficiency impairs this reaction, resulting in unstable collagen and the disease scurvy (bleeding gums, poor wound healing, joint pain). Urinary hydroxyproline is a clinical marker of collagen turnover and bone resorption.

Key Facts

  • Modified amino acid (Hyp, O) found almost exclusively in collagen, where it stabilizes the triple-helix structure through stereoelectronic effects and water-bridged hydrogen bonds.
  • Formed by post-translational hydroxylation of proline by prolyl hydroxylase, an enzyme that absolutely requires vitamin C (ascorbic acid) as a cofactor.
  • Vitamin C deficiency impairs this reaction, resulting in unstable collagen and the disease scurvy (bleeding gums, poor wound healing, joint pain).
  • Urinary hydroxyproline is a clinical marker of collagen turnover and bone resorption.
Related Terms Proline Collagen Glycine Post Translational Modification PTM

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