Compilation of free information about human parts, their function, assembly, repair, and maintenance
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.
Examples
Examples of serine proteases include:
Venoms
Certain venoms, such as those produced by poisonous 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 effects[1], including effects that are:
- cytotoxic (cell-destroying)
- hemotoxic (blood-destroying)
- myotoxic (muscle-destroying)
- hemorrhagic (bleeding)
See also
References
- ^ Hayes WK. 2005. Research on Biological Roles and Variation of Snake Venoms. Loma Linda University.
External links
- Proteolysis at eMedicine Dictionary
The content of this section is licensed under the GNU Free Documentation License (local copy). It uses material from the Wikipedia article "Proteolysis" modified December 22, 2007 with previous authors listed in its history.
