Proteolytic Enzyme


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proteolytic enzyme

[¦prōd·ē·ə¦lid·ik ′en‚zīm]
(biochemistry)
Any enzyme that catalyzes the breakdown of protein.

Proteolytic Enzyme

 

(also protease), an enzyme of the hydrolase class that is present in all living organisms. Proteolytic enzymes catalyze the hydrolysis of peptide bonds in both cellular and food proteins.

Proteolytic enzymes include peptidases (exopeptidases) and proteinases (endopeptidases). Peptidases primarily hydrolyze external peptide bonds in proteins and peptides, while proteinases hydrolyze the internal bonds. Proteolytic enzymes are subdivided according to the structural characteristics of their active center into metalloenzymes, each containing a metal atom, usually Zn, in its active center, and serine, thiolic (cys-teic), and acidic proteinases. Most of the known peptidases are metalloenzymes. Proteinases are also classed according to substrate specificity, that is, the ability to hydrolyze the bonds between specific amino-acid residues.

The sequence of amino acids in the molecules of a series of proteolytic enzymes has been determined. X-ray diffraction analysis has made it possible to determine the complete three-dimensional structure of several key proteinases, including pepsin, trypsin, and chymotrypsin. Proteolytic enzymes of the pancreas are synthesized in the form of inactive precursors—proenzymes—and therefore do not destroy the proteins of their parent tissue.

Preparations from proteolytic enzymes are used for many purposes; they are used in laboratories to determine the structure of proteins and peptides, in the food-processing industry when making cheese or tenderizing meat, in light industry to remove fur from hides and when bating leather, and in medicine to resorb thrombi and remove cataracts.

REFERENCES

Neurath, H. “Fermenty, perevarivaiushchie belki.” In Molekuly ikletki. Moscow, 1966. (Translated from English.)
Mosolov, V. V. Proteoliticheskie fermenty. Moscow, 1971.

V. V. MOSOLOV

References in periodicals archive ?
An open label study to determine the effects of an oral proteolytic enzyme system on whey protein concentrate metabolism in healthy males.
The activity of proteolytic enzymes was expressed as total proteolytic activity concentration (units [U] per milliliter) in the intracapsular fluid, whereas for offspring it was expressed as proteolytic activity per individual (U offspring[.sup.-1]).
mori SF was studied using proteolytic enzymes (collagenase F, [alpha]-chymotrypsin I-S, and protease type XXI) to degrade SF fibers and films [13].
Resolution of an Artifically Induced Hematoma and the Influence of a Proteolytic Enzyme. J Trauma.
Many pathogenic fungi produce proteolytic enzymes, and their activity determines their ability to use proteins of the host plant [13-15].
Influence of molting and starvation on the synthesis of proteolytic enzymes in the midgut gland of the white shrimp Penaeus vannamei.
It is evident that soybean meal contains good amount of protein and other nutrients which are supportive of profuse growth and secretion of proteolytic enzyme. Several other workers have also used soybean meal as a substrate in the medium for induction of proteases by Bacillus species [18, 19].
Systemic enzyme therapy, also called metabolic or proteolytic enzyme therapy, allows enzymes to enter the body where they can be used for healing rather than digestion.
Lactic acid bacteria require a wide range of amino acids for growth and their proteolytic enzyme complement is able to split most types of peptide bonds [37].
A., 2003, "Characterization of proteolytic enzyme activites in macroalga", Eur J Physol., 38, pp.