Tripeptidyl-peptidase II: a multi-purpose peptidase

Int J Biochem Cell Biol. 2005 Oct;37(10):1933-7. doi: 10.1016/j.biocel.2005.02.009. Epub 2005 Mar 9.


Tripeptidyl-peptidase II is a high-molecular weight peptidase with a widespread distribution in eukaryotic cells. The enzyme sequentially removes tripeptides from a free N-terminus of longer peptides and also displays a low endopeptidase activity. A role for tripeptidyl-peptidase II in the formation of peptides for antigen presentation has recently become evident, and the enzyme also appears to be important for the degradation of some specific substrates, e.g. the neuropeptide cholecystokinin. However, it is likely that the main biological function of tripeptidyl-peptidase II is to participate in a general intracellular protein turnover. This peptidase may act on oligopeptides generated by the proteasome, or other endopeptidases, and the tripeptides formed would subsequently be good substrates for other exopeptidases. The fact that tripeptidyl-peptidase II activity is increased in sepsis-induced muscle wasting, a situation of enhanced protein turnover, corroborates this biological role.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Aminopeptidases
  • Animals
  • Dipeptidyl-Peptidases and Tripeptidyl-Peptidases
  • Gene Expression Regulation
  • Humans
  • Models, Biological
  • Proteasome Endopeptidase Complex / metabolism
  • Serine Endopeptidases* / chemistry
  • Serine Endopeptidases* / metabolism
  • Serine Endopeptidases* / physiology


  • Aminopeptidases
  • Dipeptidyl-Peptidases and Tripeptidyl-Peptidases
  • tripeptidyl-peptidase 2
  • Serine Endopeptidases
  • Proteasome Endopeptidase Complex