proteolýzou

Proteolýza is the breakdown of proteins into smaller polypeptides or individual amino acids. This process is essential for numerous biological functions, including digestion, protein turnover, and cellular signaling. In living organisms, proteolysis is primarily carried out by enzymes called proteases, also known as peptidases. These enzymes catalyze the hydrolysis of peptide bonds that link amino acids together within a protein chain.

Proteases can be broadly classified based on the site of action within the peptide bond or their catalytic mechanism. Serine proteases, cysteine proteases, aspartic proteases, and metalloproteases are common examples, each utilizing a different amino acid residue or metal ion at their active site to facilitate the cleavage of peptide bonds.

In digestion, proteolysis begins in the stomach with pepsin and continues in the small intestine with enzymes like trypsin and chymotrypsin, which are secreted by the pancreas. These proteases break down dietary proteins into amino acids and small peptides that can be absorbed by the body.

Beyond digestion, proteolysis plays a crucial role in cellular homeostasis. It removes misfolded or damaged proteins, preventing their accumulation and potential toxicity. Proteolysis also regulates the lifespan of regulatory proteins, controlling processes like cell cycle progression, gene expression, and immune responses. Dysregulation of proteolysis is implicated in various diseases, including cancer, neurodegenerative disorders, and infectious diseases, making it a significant area of research in biochemistry and medicine.