Table 1.
Substrate specificity of some proteolytic enzymes used in molecular biology research. Proteases are classified based on their catalytic mechanisms, furthermore, the main sources and enzyme specificities are indicated. The arrows indicate the sites of cleavages.
| Enzyme | Main source | Cleavage site |
|---|---|---|
| Endopeptidases | ||
| Serine proteases | ||
| Trypsin | bovine | -Arg or Lys↓nonspecific- |
| Chymotrypsin | bovine | -Trp (or Phe, Leu, Tyr)↓nonspecific- |
| Enterokinase | bovine | Asp-Asp-Asp-Lys↓nonspecific- |
| Endoproteinase Arg-C | microbial | -Arg↓nonspecific- |
| Endoproteinase Glu-C | microbial | -Glu (or Asp)↓nonspecific- |
| Endoproteinase Lys-C | microbial | -Lys↓nonspecific- |
| Elastase | porcine | -Ala (or Gly or Val)↓nonspecific- |
| Subtilisin | microbial | -Trp (or Tyr, Phe, Leu)↓nonspecific- |
| Proteinase K | fungal | -aromatic, aliphatic or hydrophobic ↓nonspecific- |
| Thrombin | bovine | -Arg (or Lys)↓nonspecific-specific for -Leu-Val-Pro-Arg-↓Gly-Ser- |
| Factor Xa | bovine | -Arg (or Lys)↓nonspecific-specific for -Leu-Val-Pro-Arg-↓Gly-Ser- |
| WNV protease | E. coli | -Lys (or Arg)-Arg↓Gly-Ser- |
| Cysteine proteases | ||
| Bromelain | plant | -nonspecific↓nonspecific- |
| Papain | plant | -Arg (or Lys)↓nonspecific- |
| Ficin (ficain) | plant | -nonspecific↓nonspecific- |
| Rhinovirus 3C | E. coli | Gly-Pro dipeptide after the scissile bondhighly specific for -Leu-Glu-Val-Leu-Phe-Gln↓Gly-Pro- |
| TEV protease | E. coli | specific for -Gln-Asn-Leu-Tyr-Phe-Gln↓Gly- |
| TVMV protease | E. coli | specific for -Glu-Thr-Val-Arg-Phe-Gln↓Ser- |
| Metalloproteases | ||
| Endoproteinase Asp-N | microbial | -nonspecific↓Asp- |
| Thermolysin | microbial | -Leu (or Phe)↓Leu (or Phe, Val, Met, Ala, Ile)- |
| Collagenase | microbial | -Pro-neutral↓Gly-Pro- |
| Dispase | microbial | -nonspecific↓non-polar- |
| Aspartic proteases | ||
| Pepsin | porcine | -Phe (or Tyr, Leu, Trp)↓Trp (or Phe, Tyr, Leu)- |
| Cathepsin D | bovine | -Phe (or Leu)↓nonspecific (not Val, Ala)- |
| Exopeptidases | ||
| Serine proteases | ||
| Carboxypeptidase Y | yeast | -nonspecific↓nonspecific |
| Cysteine proteases | ||
| Cathepsin C | bovine | removes N-terminal dipeptide |
| DAPase | porcine | removes N-terminal dipeptide |
| Metalloproteases | ||
| Carboxypeptidase A | bovine | -nonspecific↓aromatic or branched preferred |
| Carboxypeptidase B | porcine | specific for C-terminal Arg or Lys |