Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.24.11 (CD10)
 9,792 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

PZ-peptidase is an endopeptidase that cleaves the synthetic substrate developed for clostridial collagenase, 4-phenylazobenzyloxycarbonyl-L-Pro-L-Leu-Gly-L-Pro-D-Arg (PZ-peptide). The peptidase has been purified to homogeneity from chicken embryos. The enzyme has a pH optimum of 7.5 to 8.5, and isoelectric point of 5.0, and a molecular weight of 77,000. The kinetic parameters at pH 8 and 37 degrees are: Km = 2 X 10(-4) M and Vmax = 4.2 mumol/min/mg of protein. The enzyme is inhibited by p-hydroxymercuribenzoate (100%), N-ethylmaleimide (60%), and chelating agents (40 to 60%). Maximum activity is attained in the presence of reducing agents and Ca2+, Sr2+, or Mg2+. The peptidase has no detectable action on casein, serum albumin, collagen, collagen alpha chains, various collagen peptides (alpha1)(I)-CB2, alpha1(I)-CB3, alpha1(I)-CB4), (Gly-Pro-Pro)10, or (Gly-Pro-Pro)5. It does catalyze the hydrolysis of the Hyp--Gly bond in the 17-residue collagen peptide alpha1(II)-CB6-C2 and it partially digested a mixture of collagen peptides of molecular weight 350 to 2500. A role of this peptidase in collagen breakdown appears to be restricted to a late stage when degradation products would fall in the range of 5 to 30 residues.
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PMID:PZ-peptidase from chick embryos. Purification, properties, and action on collagen peptides. 1 6

Evidence is presented for the existence of many different systems of proteolytic enzymes in human skeletal muscle. These include the lysosomal system of cathepsins as well as proteinases and peptide hydrolases that are optimally active at neutral and alkaline pH ranges. The majority of proteolytic enzymes examined are found to show increased activity in dystrophic human muscle. Moreover, a high initial rise is observed in cathepsin B1, a thiol-dependent endopeptidase of lysosomes, and in dipeptidyl peptidase IV, a membrane-associated peptidase. In addition, a calcium-activated neutral proteinase is found to be significantly elevated in muscle from patients with Duchenne dystrophy. The possible roles of these proteinases in intracellular protein catabolism and muscle wasting are discussed.
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PMID:Muscular dystrophy and activation of proteinases. 3 47

The purification and characterisation of an extracellular endo and amino-peptidase of the marine Vibrio SA1 is described. The endopeptidase was purified by ammonium sulphate precipitation, gel filtration and affinity chromatography. It had a molecular weight of approximately 31,000, a pH optimum at 7.8 and a temperature optimum at 50 C. The enzyme was rapidly inactivated at 65 C. The aminopeptidase was purified by ammonium sulphate precipitation, gel filtration and preparative polyacrylamide gel electrophoresis. This enzyme had a molecular weight of approximately 21,000, a pH optimum at 8.6 and a temperature optimum at 60 C. Both proteases were inactivated by EDTA while reactivation occurred by Ca2+, Zn2+ and Mg2+ ions. The endopeptidase hydrolysed several peptide bonds in the oxidized B-chain of insulin, particularly those involving amino groups of hydrophobic amino acid residues with bulky side chains. It was unable to hydrolyse synthetic dipeptides, but a number of tripeptides were hydrolysed at a low rate. The aminopeptidase hydrolysed leucinamide and di- and tripeptides containing hydrophobic bulky amino acids as the N-terminal residue. It was concluded that the endopeptidase and the aminopeptidase of Vibrio SA1 possess complementary specificities.
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PMID:Purification and some properties of two extracellular proteolytic enzymes produced by Vibrio SA1. 3 29

Among the five peptidase known to be located in the microvillus membrane of the renal proximal tubule are two enzymes with endopeptidase activity. Neutral endopeptidase, a zinc-dependent enzyme, has a broad specificity comparable to that of thermolysin, and like the latter may be specifically inhibited by phosphoramidon. Dipeptidyl peptidase IV, a serine enzyme, is very sensitive to inhibition by diisopropyl phosphorofluoridate. It is also capable of endopeptidase activity, hydrolysing bonds involving the carboxyl group of proline.
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PMID:Endopeptidases in the brush border of the kidney proximal tubule. 24 85

Mutants of Escherichia coli lacking in the highly penicillin-sensitive enzyme activities of D-carboxy-peptidase, transpeptidase, and endopeptidase, and with the concomitant absence of penicillin-binding protein 4 of B.G. Spratt and A.B. Pardee [(1975) Nature 254, 516-517] were isolated. The defect of these mutants is ascribed to the lack of an enzyme, D-alanine carboxypeptidase Ib. Genetic mapping studies show the mutation (dacB) to be located at 68 min on the E. coli chromosome map. The dacB mutation results in the simultaneous loss of D-alanine carboxypeptidase and penicillin-binding protein 4. The mutants grew normally under a wide range of growth conditions. We conclude that the enzyme is not a necessary component for normal peptidoglycan biosynthesis in E. coli.
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PMID:Mutants of Escherichia coli lacking in highly penicillin-sensitive D-alanine carboxypeptidase activity. 33 22

A new peptidase which splits substrates related to the peptidic chains of peptidoglycans was found in the cell cytoplasm of sporulating Bacillus sphaericus. This is a gamma-D-glutamyl-L-diaminoacid endopeptidase (endopeptidase II). It was shown to have substrate requirements different from those of the previously described gamma-D-glutamyl-(L)meso-diaminopimelate endopeptidase (endopeptidase I). The substrates for endopeptidase II are peptides of the general type: formula: (see text). Unsubstituted N-terminal L-alanine was a strict requirement for endopeptidase II activity. Specific activities were variable with the nature and the substitution of the diaminoacid C-terminal groups. The role of endopeptidase II in the biosynthesis of the spore cortex is discussed.
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PMID:[Characterisation of a new endopeptidase from sporulating Bacillus sphaericus which is specific for the gamma-D-glutamyl-L-lysine and gamma-D-glutamyl-(L)meso-diaminopimelate linkages of peptidoglycan substrates (author's transl)]. 48 88

The membrane of kidney microvilli is richly endowed with peptidases. Present information is that there are at least eight examples located in this membrane. Three of the group are known to be among the major proteins that can be identified by dodecyl sulphate electrophoresis of the purified microvillus fraction. These three peptidases, aminopeptidase M, serine peptidase (dipeptidyl peptidase IV) and neutral endopeptidase can be labelled by lactoperoxidase iodination from either the luminal or the inner surfaces of the membrane, a result consistent with the view that the polypeptide chains span the microvillus membrane. The serine peptidase has been purified by two methods, permitting a comparison of the detergent-released and proteinase-released forms. The two forms differ in the presence and absence of the hydrophobic anchor that secures the enzyme to the membrane. Preliminary studies support the view that this hydrophobic domain is relatively small and that it includes the N-terminal region of the polypeptide chain.
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PMID:Kidney microvillus peptidases--are they transmembrane proteins? 61 79

Dipeptidyl peptidase IV, an enzyme that releases dipeptides from substrates with N-terminal sequences of the forms X-Pro-Y or X-Ala-Y, was purified 300-fold from pig kidney cortex. The kidney is the main source of the enzyme, where it is one of the major microvillus-membrane proteins. Several other tissues contained demonstrable activity against the usual assay substrate glycylproline 2-naphthylamide. In the small intestine this activity was greatly enriched in the microvillus fraction. In all tissues examined, the activity was extremely sensitive to inhibition by di-isopropyl phosphorofluoridate (Dip-F), but relatively resistant to inhibition by phenylmethylsulphonyl fluoride. It is a serine proteinase which may be covalently labelled with [32P]Dip-F, and is the only enzyme of this class in the microvillus membrane. The apparent subunit mol.wt. estimated by sodium dodecyl-sulphate/polyacrylamide-gel electrophoresis and by titration with [32P]Dip-F was 130 000. Gel-filtration and sedimentation-equilibrium methods gave values in the region of 280 000, which is consistent with a dimeric structure, a conclusion supported by electron micrographs of the purified enzyme. Among other well-characterized serine proteinases, this enzyme is unique in its membrane location and its large subunit size. Investigation of the mode of attack of the peptidase on oligopeptides revealed that it could hydrolyse certain N-blocked peptides, e.g. Z-Gly-Pro-Leu-Gly-Pro. In this respect it is acting as an endopeptidase and as such may merit reclassification and renaming as microvillus-membrane serine peptidase.
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PMID:Dipeptidyl peptidase IV, a kidney brush-border serine peptidase. 96 53

Procollagen peptidase was recovered from the medium of human and mouse fibroblast cultures by precipitation with ammonium sulfate. The test substrate for the in vitro enzymatic reaction was radioactively-labeled, disulfide-linked procollagen prepared from the medium of human fibroblast cultures. The enzymatic digests were analyzed by electrophoresis in polyacrylamide gets containing sodium dodecyl sulfate and urea. The human and mouse enzymes reacted with the substrate to generate the same intermediates and final products. Procollagen peptidase acts as an endopeptidase which cleaves each of the three procollagen chains in turn. The final products of the reaction are collagen and a three-chain, disulfide-linked fragment derived from the nonhelical aminoterminal residues of procollagen.
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PMID:Procollagen peptidase: its mode of action on the native substrate. 116 12

Dipeptidase activity in homogenate from small intestinal mucosa is determined according to the method of Josefsson (1965) in 45 patients with chronic non-specific enteritis. The majority of the enzymes are of the endopeptidase group, degrading the dipeptides of the neural aminoacids; glycyl-alanine, alanyl-l-valine, glycyl-l-isoleucine, analyl-glycine, leucyl-l-leucine, alanyl-l-leucine, alanyl-l-proline, glycyl-l-glutamic acid; only one enzyme-glycyl-l-leucine dipeptidase belongs to the enzymes of the brush-like zone of the enterocyte. The glycyl-l-alanine dipeptidase enzyme activity was established to be decreased with 49,2 per cent, glycyl-l-leucine--with 33,2 per cent, glycyl-l-valine with 19,6 per cent, glycyl-l-isoleucine--with 61 per cent, etc. The diminished enzyme activity corresponds, in the majority of the cases, to the severity of the disease and to the degree of the histological changes. It does not reach the decreased degree, found in the patients with coliac sprue. In a series of cases the enzymatic activity does not correspond to the morphological changes: "normal activity" and decreased peptidase activity were found in six cases and in two cases--"partial mucosal atrophy" and normal or elevated peptidase activity. Very likely, the pointed out enzymes, are of a substantial importance for the pathogenetic digestive and resorbtive disturbances in chronic non-specific enteritis, especially protein disturbances.
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PMID:[Dipeptidase activity in the small intestine of patients with chronic nonspecific enteritis]. 118 89


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