Proteolysis is the breakdown of proteins into smaller polypeptides or amino acids. This generally occurs by the hydrolysis of the peptide bond, and is most commonly achieved by cellular enzymes called proteases, but may also occur by intramolecular digestion, as well as by non-enzymatic methods such as the action of mineral acids and heat.
Proteolysis in organisms serves many purposes; for example, digestive enzymes break down proteins in food to provide amino acids for the organism, while proteolytic processing of polypeptide chain after its synthesis may be necessary for the production of an active protein. It is also important in the regulation of some physiological and cellular processes, as well as preventing the accumulation of unwanted or abnormal proteins in cells.
Read more about Proteolysis: Post-translational Proteolytic Processing, Protein Degradation, Proteolysis in Cellular Regulation, Regulatiory Domains in Proteolysis, Proteolysis and Diseases, Non-enzymatic Proteolysis, Laboratory Applications, Venoms