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Endopeptidase
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This article may require cleanup to meet Wikipedia's quality standards. Please discuss this issue on the talk page or replace this tag with a more specific message. This article has been tagged since December 2006. |
Endopeptidase are a type of peptidase, and are contrasted to exopeptidases.
Endopeptidases chemically break peptide bonds within the molecule.
They are usually very specific for certain amino acids. Endopeptidase cleaves the middle of the polypeptide chain.
Examples of endopeptidases include:
- Trypsin - cuts after Arg or Lys, unless followed by Pro. Very strict.
- Chymotrypsin - cuts after Phe, Trp, or Tyr, unless followed by Pro. Cuts more slowly after Asn, His, Met or Leu.
- Elastase - cuts after Ala, Gly, Ser, or Val, unless followed by Pro.
- Thermolysin - cuts before Ile, Met, Phe, Trp, Tyr, or Val, unless preceded by Pro. Sometimes cuts after Ala, Asp, His or Thr. Heat stable.
- Pepsin - cuts before Leu, Phe, Trp or Tyr, unless preceded by Pro. Also others, quite nonspecific; works best at pH 2.
- Endopeptidase V8 - cuts after Glu.
Endopeptidase, Exopeptidase (Angiotensin-converting enzyme)
Cysteine protease: Papain, Cathepsin (B, C, K), Caspase, Calpain
Aspartic acid protease: Pepsin - Chymosin - Renin - Plasmepsin - Signal peptide peptidase