An exopeptidase is any peptidase that catalyzes the cleavage of the terminal (or the penultimate) peptide bond; the process releases a single amino acid, dipeptide or a tripeptide from the peptide chain.[1] Depending on whether the amino acid is released from the amino or the carboxy terminal (N-terminus or C-terminus), an exopeptidase is further classified as an aminopeptidase or a carboxypeptidase, respectively. Thus, an aminopeptidase, an enzyme in the brush border of the small intestine, will cleave a single amino acid from the amino terminal, whereas carboxypeptidase, which is a digestive enzyme present in pancreatic juice, will cleave a single amino acid from the carboxylic end of the peptide.
Some examples of exopeptidases include:[1]
- Carboxypeptidase A - cleaves C-terminal Phe, Tyr, Trp, or Leu
- Carboxypeptidase B - cleaves C-terminal Lys or Arg
- Aminopeptidase - cleaves any N-terminal amino acid
- Prolinase - cleaves N-terminal Pro from dipeptides[2]
- Prolidase - cleaves C-terminal Pro from dipeptides[3]
See also
External links
- Exopeptidases at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
References
- 1 2 Škárka, Bohumil (1992). Biochémia (in Slovak). Bratislava: Alfa. pp. 360, 688. ISBN 80-05-01076-1.
- ↑ "Definition of prolinase | Dictionary.com". www.dictionary.com. Retrieved 2022-04-09.
- ↑ Namiduru, E. S. (2016). "Prolidase". Bratislavske Lekarske Listy. 117 (8): 480–485. doi:10.4149/bll_2016_093. ISSN 0006-9248. PMID 27546702.