Prolyl

Part of speech: noun

Definitions

1. A specific chemical or molecular structure associated with proline, often used in biochemistry and molecular biology
2. Referring to a segment in a peptide or protein chain that includes the amino acid proline, relevant in structural roles
3. Pertaining to the prolyl group or derived compounds, commonly studied in the field of amino acid research

Etymology: "Prolyl" names the group left behind when a hydrogen atom is removed from proline, an amino acid found in proteins. The ending does most of the historical work. "-yl" comes from the Greek "hylē," meaning wood or raw material. In the 1830s, Justus von Liebig and Friedrich Wöhler proposed that a cluster of atoms could pass unchanged through a series of reactions, and they used "benzoyl" as their example. The suffix was a metaphor: a stable core that could be shaped into different compounds, like timber. Proline itself is much younger. Emil Fischer isolated it from casein, a milk protein, in 1901, and its name reflects the pyrrolidine ring in its structure. Chemists then attached the "-yl" ending to that name to describe the group.