Exopeptidases
Exopeptidases are enzymes from the group of peptidases . Peptidases break down proteins by hydrolysing the peptide bonds . In contrast to the endopeptidases, the exopeptidases only cleave terminal peptide bonds of the amino acid sequence . The products are free amino acids as well as di- and tripeptides .
Classification
The exopeptidases can be divided into aminopeptidases , carboxypeptidases and di- and tripeptidases . Aminopeptidases cleave the polypeptide chain at the N-terminus , the dipeptidyl peptidases can release a dipeptide , the tripeptidyl peptidases a tripeptide . Exopeptidases acting at the C-terminus release individual amino acids through the action of carboxypeptidases or dipeptides through the reactions catalyzed by peptidyl dipeptidases.
In addition, there are exopeptidases that specifically cleave dipeptides (dipeptidases) or remove terminal substituted , cyclized or isopeptide- linked amino acids (omega-peptidases).