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The inactive or nearly inactive precursor of an enzyme, converted into an active enzyme by proteolysis. Also called zymogen.


(Biochemistry) the inactive form of an enzyme; zymogen


(ˈzaɪ mə dʒən, -ˌdʒɛn)

any of various enzyme precursor molecules that may change into an enzyme as a result of catalytic change. Also called proenzyme.
[< German (1875); see zymo-, -gen]
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.proenzyme - any of a group of compounds that are inactive precursors of enzymes and require some change (such as the hydrolysis of a fragment that masks an active enzyme) to become active
organic compound - any compound of carbon and another element or a radical
References in periodicals archive ?
The conversion of the proenzyme to the active form is an extensively studied system of enzymatic checks and balances known as the phenoloxidase cascade that closely regulates the release and activation of phenoloxidase at the appropriate time and place (Ashida and Yamazaki, 1990; Sugumaran and Kanost, 1993; Soderhall and Cerenius, 1998).
Proenzyme prostate specific antigen (pPSA) does a better job of detecting prostate cancer and helping prevent unnecessary biopsies than free PSA (fPSA) does, according to the results of a preliminary study reported in the February issue of Urology.
It is a dormient proenzyme maintained in an inactive structural conformation, by an Asp-Asp-Asp regulatory tripeptide named "safety catch" [16].
Becker had recently discovered that the first component (C1), subsequently identified as subunit C1q, was a protease proenzyme that was activated by contact with antigen-antibody complexes.
Caspase-3 is synthesized as inactive proenzyme, where upon cleavage at Asp175/Ser176, is converted to the active enzyme.
Activation of the proenzyme involves proteolytic removal of the N-terminal proregion containing the cysteine switch motif conserved in matrix metalloproteinases (18).
Evidence that cathepsin L-like proteinase is stored as a latent, acid-activable proenzyme. Arch.
Total MMP-2 including active MMP-2, pro-MMP-2, and TIMP complexed matrix metalloproteinase 2 as well as active and proenzyme of MMP-9 concentrations were measured.
It is a cytosolic protein as an inactive 32-kDa proenzyme and is activated by proteolytic cleavage into the 20 kDa (p20) and 11 kDa (p11) active subunits.
The levels of the proenzyme and activated forms of cathepsin D also increased with increasing hydrogen peroxide concentrations (Figure 2(c)).
The protease to be measured converts a proenzyme into an active enzyme (detection enzyme), and the activity of the latter is detected (Fig.