Glycosylase

Part of speech: noun

Definitions

1. An enzyme that catalyzes the breaking of glycosidic bonds linking sugar units in carbohydrates and glycoproteins
2. A biological catalyst that hydrolyzes the bonds joining sugar molecules within complex carbohydrates or sugar-bearing proteins
3. Any protein enzyme able to split the glycosidic linkages that hold monosaccharide units together in larger sugar structures

Etymology: Glycosylase is a technical coinage, built in plain view from two older pieces of chemistry. "Glycosyl" names the sugar-derived group that gets transferred from one molecule to another, and the "-ase" ending marks the word as the name of an enzyme. The whole word is therefore a description of what the enzyme does: it attaches or detaches a glycosyl group. The "glyc-" part reaches back to ancient Greek "glukus," meaning "sweet," which also gave English "glucose." Chemists in the nineteenth century borrowed that stem to name sugars, and "glycosyl" was formed from it on the same pattern as other chemical group names ending in "-yl." The "-ase" suffix comes from "diastase," the first enzyme ever identified, which was isolated from germinating barley in the 1830s. Because of that precedent, "-ase" became the standard ending for enzyme names, and "glycosylase" followed the pattern.