What is the Difference Between Endopeptidase and Exopeptidase?

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The main difference between endopeptidase and exopeptidase lies in the location of the peptide bonds they break.

  • Endopeptidases break peptide bonds within the protein molecule, specifically targeting nonterminal amino acids. They do not break down peptides into monomers but rather result in smaller peptide chains. Examples of endopeptidases include trypsin, chymotrypsin, and elastase.
  • Exopeptidases break peptide bonds at the terminals of the protein molecule, targeting one or two terminal amino acids. They can break down proteins into single amino acids. Exopeptidases can be further classified into aminopeptidases, which remove amino acids from the N-terminus, and carboxypeptidases, which remove amino acids from the C-terminus.

In summary, endopeptidases break peptide bonds within the protein molecule, while exopeptidases break peptide bonds at the terminals of the protein molecule. The action of endopeptidases results in smaller peptide chains, whereas exopeptidases can break down proteins into single amino acids.

Comparative Table: Endopeptidase vs Exopeptidase

Here is a table comparing the differences between endopeptidase and exopeptidase:

Feature Endopeptidase Exopeptidase
Definition Endopeptidases are enzymes that break peptide bonds within the primary structure of proteins, resulting in smaller fragments. Exopeptidases are enzymes that break peptide bonds at the terminals of the protein molecule, cleaving amino acids off the terminal end.
Location Endopeptidases break peptide bonds within the protein, not at the terminals. Exopeptidases break peptide bonds at the terminals of the protein molecule.
Subtypes Endopeptidases do not have specific subtypes. Exopeptidases have two subtypes: carboxypeptidases and aminopeptidases. Carboxypeptidases remove an amino acid from the end with a free carboxyl group, and aminopeptidases act on the terminal amino acid with a free amino group.
Examples Examples of endopeptidases include pepsin, chymotrypsin, thermolysin, and trypsin. Examples of exopeptidases include carboxypeptidase and aminopeptidase.

In summary, endopeptidases break peptide bonds within the protein, while exopeptidases break peptide bonds at the terminals.