Proteolysis is the directed degradation ("digestion") of proteins by cellular enzymes called proteases or by intramolecular digestion.


Proteolysis is used by the cell for several purposes. They include:
* Removal of N-terminal methionine residues after translation.
* Removal of the signal sequence of peptides after their transport through a membrane
* Separation of viral proteins that were translated from a polycistronic mRNA
* Digestion of proteins from foods as a source of amino acids
* Conversion of predecessor-proteins (proenzymes, zymogens, prehormones) into their final structures.
* Degradation of cyclins at different stages of the cell cycle.

Proteolysis is also used in research and diagnostic applications:
* In-gel digestion of proteins after separation by gel electrophoresis for the identification by mass spectrometry.
* Digestion of proteins in solution for proteome analysis by LC-MS.


Examples of serine proteases include:
* trypsin
* chymotrypsin
* elastase


Certain venoms, such as those produced by venomous snakes, can also cause proteolysis. These venoms are, in fact, highly-evolved digestive fluids that begin their work outside of the body. Proteolytic venoms cause a wide range of toxic effectsHayes WK. 2005. [ Research on Biological Roles and Variation of Snake Venoms.] Loma Linda University.] , including effects that are:
* cytotoxic (cell-destroying)
* hemotoxic (blood-destroying)
* myotoxic (muscle-destroying)
* hemorrhagic (bleeding)

ee also

* Proteasome
* In-gel digestion


External links

* [ Proteolysis MAP from Center on Proteolytic Pathways]

Wikimedia Foundation. 2010.

См. также в других словарях:

  • Proteolysis — Pro te*ol y*sis, n. [NL. See {Proteolytic}.] (Physiol. Chem.) The digestion or dissolving of proteid matter by proteolytic ferments. [1913 Webster] …   The Collaborative International Dictionary of English

  • proteolysis — [prōt΄ē äl′ə sis] n. [ModL: see PROTEIN & LYSIS] Biochem. the breaking down of proteins, as by gastric juices, to form simpler substances proteolytic [prōt΄ēō lit′ik] adj …   English World dictionary

  • proteolysis — proteolytic /proh tee euh lit ik/, adj. /proh tee ol euh sis/, n. Biochem. the breaking down of proteins into simpler compounds, as in digestion. [1875 80; proteo (comb. form repr. PROTEIN) + LYSIS] * * * Process in which a protein is broken down …   Universalium

  • proteolysis — Cleavage of proteins by proteases. Limited proteolysis occurs where proteins are functionally modified (activated in the case of zymogens) by highly specific proteases …   Dictionary of molecular biology

  • proteolysis — proteolizė statusas T sritis chemija apibrėžtis Hidrolizinis baltymų skaidymas iki aminorūgščių. atitikmenys: angl. proteolysis rus. протеолиз …   Chemijos terminų aiškinamasis žodynas

  • proteolysis — noun Etymology: New Latin Date: 1880 the hydrolysis of proteins or peptides with formation of simpler and soluble products …   New Collegiate Dictionary

  • proteolysis — noun The hydrolysis of proteins into peptides and amino acids; especially as part of the digestion of food …   Wiktionary

  • proteolysis — The decomposition of protein; primarily via the hydrolysis of peptide bonds, both enzymatically and nonenzymatically. [proteo + G. lysis, dissolution] * * * pro·te·ol·y·sis .prōt ē äl ə səs n, pl y·ses .sēz the hydrolysis of proteins or peptides… …   Medical dictionary

  • proteolysis — prəʊtɪ É‘lÉ™sɪs / É’l n. dissolution of proteins, breaking down of proteins …   English contemporary dictionary

  • proteolysis — [ˌprəʊtɪ ɒlɪsɪs] noun Biochemistry the breakdown of proteins or peptides into amino acids by the action of enzymes. Derivatives proteolytic adjective proteolytically adverb …   English new terms dictionary

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