Exopeptidases

Part of speech: noun

Definitions

1. An enzyme that catalyzes the hydrolysis of peptide bonds at the terminal ends of peptide chains, resulting in the release of amino acids
2. A type of proteolytic enzyme involved in protein digestion by sequentially removing amino acids from the ends of peptides
3. These enzymes play a crucial role in breaking down proteins into smaller peptides or free amino acids for absorption in living organisms

Etymology: "Exopeptidases" is the plural of "exopeptidase," a technical coinage built from three parts. The prefix "exo-" comes from Greek "exō," meaning "outside" or "external," and here marks the action at the outer ends of a chain. "Peptide," the building block of proteins, is a modern scientific term formed in the late 19th century from Greek "pepsis," digestion. The suffix "-ase," used for enzymes since the 19th century on the model of "diastase," completes the name. Put together, an exopeptidase is an enzyme that works from the outside of a protein chain, snipping off one amino acid at a time from either the amino or the carboxyl end, rather than cutting the chain in the middle. The name is a precise description of its job, which is why biochemists could read the word and know exactly what the enzyme does.

Synonyms: proteolytic enzymes, peptidases, digestive enzymes, proteinases, enzymes