Endooligopeptidase A activity in rabbit heart: Generation of enkephalin from enkephalin containing peptides

Thiol-dependent metallo-endopeptidase characteristics of Pz-peptidase in rat and rabbit

“…Recent work with rat Pz-peptidase showed it to be identical with 'endopeptidase 24.15' (EC 3.4.24.15) , an enzyme regarded as a metallo-peptidase (Orlowski et al, 1989). In contrast, our study of rabbit muscle Pz-peptidase highlighted its cysteine-endopeptidase-like characteristics, and indeed we showed rabbit Pz-peptidase to be identical with 'endooligopeptidase A' (EC 3.4.22.19) , an enzyme considered to be a cysteine peptidase (Cicilini et al, 1988). The emphasis that has been placed on the metal-ion-dependence of rat Pz-peptidase as opposed to the thiol-dependence of the rabbit enzyme could appear to raise the question of whether these are separate enzymes rather than forms of a single enzyme.…”

“…These findings are consistent with the reports by Orlowski et al (1983), describing activation of rat brain soluble metallo-endopeptidase by low dithiothreitol concentration, and by Orlowski et al (1989), who found the more highly purified enzyme from rat testis to be less active in 0.4 mM-dithiothreitol than in the 0.2 mm concentration used in their standard assay. The thiol activation of the rabbit enzyme has been clearly demonstrated (Cicilini et al, 1988;.…”

“…The results obtained by Camargo and co-workers can be attributed to the use of rather mild treatment with EDTA. Thus, with the heart enzyme, Cicilini et al (1988) used only 2 mM-EDTA for 15 min, obtaining up to 35 % inactivation. Our own work with the rabbit muscle enzyme involved aged preparations and an assay procedure that was less specific for Pz-peptidase (lacking the diisopropyl phosphorofluoridate treatment of the samples).…”

Crystal Structure of the E.coli Dipeptidyl Carboxypeptidase Dcp: Further Indication of a Ligand-dependant Hinge Movement Mechanism

“…The metallopeptidases of the M3 family (belonging to the gluzincin superfamily/clan MA; MER-OPS data base) 1 contain a single catalytic zinc ion, which is ligated by the two His imidazole sidechains of the His-Glu-Xaa-Gly-His (HEXXH) zinc binding consensus sequence and by the Glu sidechain of a downstream Glu-(Xaa) 3 -Asp motif, as exemplified by the prototypical bacterial zinc endopeptidase thermolysin. 2 This M3 family subdivides into the small subfamily M3B, whose members are enzymes only from bacteria, and into the widespread subfamily M3A, which comprises a number of high-molecular mass endo-as well as exopeptidases from bacteria, archaea, protozoa, fungi, plants and animals.…”

Probing the catalytically essential residues of a recombinant dipeptidyl carboxypeptidase from Escherichia coli

“…This M3 family subdivides into the small subfamily M3B, whose members include only bacterial enzymes, and into the widespread subfamily M3A, which comprises a number of high-molecular mass endo-as well as exo-peptidases from bacteria, archaea, protozoa, fungi, plants, and animals. Well-known mammalian/eukaryotic M3A endopeptidases are the thimet oligopeptidase (M03.001; alias endopeptidase 3.4.24.15) (Cicilini et al 1988), neurolysin (M03.002; alias endopeptidase 3.4.24.16) (Checler et al 1986), and the mitochondrial intermediate peptidase (M03.006). The first two are intracellular enzymes, which act only on short substrates of less than 20 amino acid residues (Knight et al 1995), while the latter cleaves N-terminal octapeptides from proteins during their import into the mitochondria (Isaya & Kalousek 1995).…”