Proteolysis
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 monocistronic mRNA
- Digestion of proteins from foods as a source of amino acids
- Conversion of predecessor-proteins (proenzymes, zymogenes, prehormones) into their final structures.
Examples of proteases are
trypsin and
chymotrypsin.