Hydroxyproline

Part of speech: noun

Definitions

1. A non-proteinogenic amino acid that is formed by the post-translational modification of proline and is a major component of collagen
2. An amino acid derived from proline that plays a vital role in the stability and structure of collagen in connective tissues
3. A substance essential for maintaining the integrity of collagen fibers in various tissues, contributing to tissue repair and maintenance

Etymology: Hydroxyproline is a compound name built from two chemical parts. "Proline" is the amino acid itself, and "hydroxy-" is the chemists' prefix meaning that a hydroxyl group (an oxygen atom bonded to a hydrogen) has been attached to the molecule. In other words, the name is a literal description of the structure: proline with one extra hydroxyl group added. The name tells you what the molecule is, not where it was first found. Chemists of the nineteenth and early twentieth centuries used this kind of systematic naming to label compounds that differed from a known parent by a substituent, so "hydroxyproline" follows the same logic as words like "hydroxybutyric." Its importance lies in biology: this modified form of proline appears in collagen, where it helps the protein chains fold into their stable triple-helix shape. That function is why the name matters to physiologists, even though the word itself is a plain piece of chemical bookkeeping.

Synonyms: hyp, oxidized proline