from The American Heritage® Dictionary of the English Language, 5th Edition.
- noun The inactive or nearly inactive precursor of an enzyme, converted into an active enzyme by proteolysis.
from the GNU version of the Collaborative International Dictionary of English.
- noun (Bioch.) Any one of a class of proteins that are converted, in the normal course of cellular metabolism, into one or more active enzymes; also called
zymogen. The conversion usually is due to a specific cleavage of a peptide bond by another enzyme, or may be due to acid.
from Wiktionary, Creative Commons Attribution/Share-Alike License.
- noun biochemistry Any
inactive precursorof an enzymethat is converted to an enzyme by proteolysis; a zymogen
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- noun 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
Sorry, no etymologies found.
That in the same system one can with RIA measure both an enzyme and its proenzyme and other inactive forms has both advantages and disadvantages, depending on the problem under investigation.
TPP1 is synthesized as an inactive proenzyme (pro-TPP1) that is proteolytically processed into the active enzyme after exposure to low pH in vitro or targeting to the lysosome in vivo.
The proenzyme structure reveals suboptimal catalytic triad geometry with its propiece linker partially blocking the substrate-binding site, which together serve to prevent premature activation of the protease.