- A termination denoting 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. [Fr. (diast)ase, an amylase that converts starch to maltose, fr. G. diastasis, separation, fr. dia-, through, apart, + stasis, a standing]
* * *suffix denoting
* * *a word termination used in forming the names of enzymes, ordinarily affixed to a stem that indicates the substrate, the type of reaction catalyzed, or a combination of these factors.
Medical dictionary. 2011.