Proteolysis

Proteolysis

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

Purposes

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

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

Venoms

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. [http://www.llu.edu/llu/grad/natsci/hayes/research-c-venom.html?PHPSESSID=55842bf3eeb83dcdfec66c45b91925fc 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

References

External links

*
* [http://www.proteolysis.org/ Proteolysis MAP from Center on Proteolytic Pathways]


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Look at other dictionaries:

  • 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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