Proteolysis

Proteolysis is the directed degradation (digestion) of proteins, either by cellular enzymes called protease?s, or by intramolecular digestion.

Proteolysis is used by the cell for several purposes. They are:

• Removal of N-terminal? methionine? residues after translation.
• Removal of the [signal sequence]? of peptides after transport through a membrane]
• Separation of viral proteins that were translated from a monocistronic? mRNA.
• Digestion of proteins.
• Conversion of predecessor-proteins (proenzyme?s, zymogene?s, prehormone?s) into their final structure.

Examples for proteases are trypsin and chymotrypsin.