Structural features of C15 and M1 peptidases for recognizing their peptide substrates

Abstract

Peptidases are enzymes that irreversibly hydrolyze a peptide bond in a polypeptide. Peptidases are found in all the known organism. They have various application in food industry, leather industry, silver recovery, waste management, bio-engineering, bio-medical, pharmaceutical etc. Peptidases can be grouped into four major classes according to the key catalytic group in the active site: aspartic peptidase, cysteine peptidase, metallopeptidase and serine peptidase. These have also been classified on the basis of the position of target peptide bond: endopeptidase, aminopeptidase and carboxypeptidase. There is a special class of peptidases which hydrolyze terminal residue from the peptide or protein which is cyclized, substituted or linked by iso-peptide bond called as omega-peptidase (EC 3.4.19.). The omega-peptidases are a diverse collection of enzymes which cleaves variety of modified residue such as N-acyl amino acid (lipid amino acid linkage -involve in cell communication), beta-aspartyl, N-formyl methionine, gamma glutamyl, ubiquitin, leukotriene C4, pyroglutamate modification from either N or Cterminus of peptides or proteins.