Proenzyme(redirected from proenzymes)
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(also proferment, zymogen, preenzyme), an inactive precursor of enzymes. Proenzymes form during the biosynthesis of enzymes. They are converted into active enzymes following limited proteolysis. The fission of usually one of the peptide bonds of the proenzyme molecule, which results in a partial structural change in the molecule, leads to the formation of the enzyme’s active center. Many proteolytics that are present in animals and bacteria, as well as phospholipase, are synthesized as proenzymes. Typical proenzymes include pepsinogen, trypsinogen, and prothrombin. Proenzymes are biologically important because they inhibit premature enzymatic activity in those cells and tissues where there is enzyme biosynthesis.