How can hydrolysis break peptide bonds in proteins?

Hydrolysis is a chemical reaction in which water acts as a reactant to break down complex molecules, such as proteins, into their constituent parts. In the context of proteins, this process involves the cleavage of peptide bonds—the chemical bonds connecting the amino acid residues in a protein chain.123

There are two primary ways this cleavage is achieved:

• Enzymatic Hydrolysis: In biological systems, proteolytic enzymes (such as pepsin, trypsin, and chymotrypsin) catalyze the hydrolysis of proteins during digestion and cellular maintenance. These enzymes accelerate the reaction, allowing the body to break down proteins into smaller peptides or individual amino acids for assimilation.41
• Chemical Hydrolysis: In laboratory settings, peptide bonds can be broken by boiling a protein in a concentrated acid, such as hydrochloric acid. This method is frequently used to determine the amino acid composition of a protein.2

By introducing water across the peptide bond, the reaction effectively reverses the process of amide formation, resulting in the separation of the amino acid chain.13