online medical dictionary | definition of -ase

<suffix>

<biochemistry> A combining form or suffix that denotes an enzyme, suffixed to the name of the substance (substrate) upon which the enzyme acts; e.g., phosphatase, lipase, proteinase. May also indicate the reaction catalyzed e.g., decarboxylase, oxidase. Enzymes named before the convention was established generally have an -in ending; e.g., pepsin, ptyalin, trypsin.

Origin: Fr. (diast)ase, an amylase that converts starch to maltose, fr. G. Diastasis, separation, fr. Dia-, through, apart, + stasis, a standing

(05 Mar 2000)