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)

An acid protease produced by the thermophilic fungus Penicillium duponti K 1014 has been purified by consecutive ion-exchange and gel permeation chromatography, and crystallized from aqueous acetone solution. The purified endopeptidase gave a symmetrical schlieren peak by sedimentation velocity, and was found to be homogeneous upon disc gel electrophoresis at pH 9.5. The enzyme was most active at pH 2.5 against milk casein and showed high thermostability. An isoelectric point of 3.81 was found by isoelectric focusing. A minimum molecular weight of 41 590 was calculated from the amino acid composition, adopting an arginine content of one residue per mole of enzyme. This minimum molecular weight is in good agreement with the value of 41 000 previously found by gel permeation (Hashimoto, H., Iwaasa, T., and Yokotsuka, T. (1973), Appl. Microbiol. 25, 578). Besides the thermostability, the purified P. duponti protease differs from other well-characterized acid proteases in that it contains carbohydrate, 4.33% expressed as glucose. The enzyme was not affected by p-bromophenacyl bromide, but was completely inactivated by alpha-diazo-p-bromoacetophenone, diazoacetyl-DL-norleucine methyl ester, and diazoacetylglycine ethyl ester, in the presence of Cu2+. The complete inactivation of the protease by diazoacetyl-DL-norleucine methyl ester resulted in the specific incorporation of 1 mol of norleucine/mol of enzyme. On the basis of similar behavior of other acid proteases toward this inactivator, the results suggest the presence at the active site of an unusually reactive carboxyl group, involved in the catalytic function. The naturally occurring pepsin inhibitor of Streptomyces naniwaensis [Murao, S., and Satoi, S. (1970), Agric. Biol. Chem. 34, 1265] inhibited also the protease, at a threefold molar excess with respect to the enzyme.
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PMID:Purification and properties of the thermostable acid protease of Penicillium duponti. 0 87

An aminopeptidase was isolated from the culture filtrate of Clostridium histolyticum and purified to homogeneity. Absence of endopeptidase activity in the purified preparation was demonstrated. Gel filtration on a calibrated column indicates an apparent molecular weight of 340000 for the native enzyme. Gel electrophoresis of the denatured enzyme in the presence of dodecylsulfate in constant acrylamide concentration and in a concentration gradient, resulted in the appearance of a single component for which a molecular weight of 51000 and 59000 respectively, was calculated. From mobilities of crosslinked and denatured protein species a molecular weight of 56000 was obtained for the monomer. Specificity studies show that the enzyme cleaves all types of N-terminel amino acid residues including proline and hydroxyproline from small peptides and from polypeptides. The peptide bond formed between an N-terminal amino acid residue and proline is not cleaved by the enzyme. The combined action of aminopeptidase-P and clostridal aminopeptidase leads to complete hydrolysis of the proline-rich nonapeptide bradykinin. Low rates of hydrolysis was observed for charged residues, and amides of amino acids. Kinetic studies with five tripeptides of the general structure X-Gly-Gly, where X stands for Leu, Phe, Val, Ala, or Pro, show a decrease in Km with the increasing size of the hydrophobic side chain of X. The highest Kcat values are observed with proline and alanine. In the series Pro-Gly, Pro-Gly-Pro, Pro-Gly-Pro-Pro, the last peptide is the best substrate, indicating an active site complementary to at least four amino acid residues. The enzymatic activity is dependent on the presence of divalent cations, maximal activation being reached with Mn2+ and Co2+. The optimal pH for the Mn2+ and Co2+- activated enzyme is 8.6 and 8.2 respectively. The optimal temperature is 40 degrees C. Inhibition of the aminopeptidase was achieved with Zn2+, Cu2+ and p-mercuribenzoate, but not with diisopropylphosphofluoridate.
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PMID:An extracellular aminopeptidase from Clostridium histolyticum. 0 18

We examined the in vitro degradation of human pancreastatin-52 (hPST-52) and a larger molecular form (approximate 15 kDa) of human PST by an enzyme extract from human kidney. The PST-degrading activity was determined from the amount of immunoreactive PST remaining after incubation of hPST-52 or the larger molecular form with the enzyme extract. Human PST-52 was degraded to smaller molecular forms within 30 min, but the larger molecule was not degraded within 90 min. Phosphoramidon, an inhibitor of endopeptidase, metal ion chelators (EDTA and 1, 10-phenanthroline) and Cu2+ prevented the degradation of hPST-52. These results indicated that the enzyme in the kidney extract degraded hPST-52 and smaller forms of the peptide, but had no effect on the 15 kDa form.
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PMID:Degradation of human pancreastatin-52 by human kidney extract. 174 Sep 68

An endopeptidase has been purified to homogeneity from a crude cell extract of Lactococcus lactis subsp. cremoris Wg2 by a procedure that includes diethyl-aminoethane-Sephacel chromatography, phenyl-Sepharose chromatography, hydroxylapatite chromatography, and fast protein liquid chromatography over an anion-exchange column and a hydrophobic-interaction column. Gel filtration and sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicated a molecular mass of the purified enzyme of 70,000 Da. The endopeptidase can degrade several oligopeptides into various tetra-, tri-, and dipeptides. The endopeptidase has no aminopeptidase, carboxypeptidase, dipeptidase, or tripeptidase activity. It is optimally active at pH 6.0 to 6.5 and in the temperature range of 30 to 38 degrees C. The enzyme is inactivated by the chemical agents 1,10-phenanthroline, ethylenedinitrilotetraacetate, beta-mercaptoethanol, and phenylmethylsulfonyl fluoride and is inhibited by Cu2+ and Zn2+. The ethylenedinitrilotetraacetate- or 1,10-phenanthroline-treated enzyme can be reactivated by Co2+. Immunoblotting with specific antibodies raised against the purified endopeptidase indicated that the enzyme is also present in other Lactococcus spp., as well as in Lactobacillus spp. and Streptococcus salivarius subsp. thermophilus.
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PMID:Purification and characterization of an endopeptidase from Lactococcus lactis subsp. cremoris Wg2. 178 32

Recent studies have shown that some manifestations of cis-diamminedichloroplatinum (II) (cis-Pt) induced nephrotoxicity in animals may be exacerbated if the animals are nutritionally deprived of copper. The objective of the present study was to determine the effects of cis-Pt induced toxicity on enzyme activities in the kidney microvilli of rats with different copper statuses. Weanling male rats were fed copper-deficient (CuD) (less than 1 mg/kg Cu of diet) or copper-adequate (CuA) (5 mg/L of Cu in drinking water) regimens. After 24 days, rats were given i.v. injections of either cis-Pt (5 mg/kg BW) or saline in a 2 x 2 factorial design. At days 2 and 4 post-injection rats were killed and tubular microvilli isolated from the kidney cortex. Each preparation was assayed for the activities of 5 membrane-bound enzymes. Angiotensin-I converting enzyme (ACE) activity was 20 to 30% higher in the microvilli of CuD rats than in controls. Cis-Pt treatment enhanced ACE activity as well, and activity in treated rats was 60 to 110% higher than in controls. At day 2 there was a 20% greater increase in ACE activity in cis-Pt-treated CuD rats than in CuA rats. Aminopeptidase N activity was 35% lower in CuD rats than controls, but activity was not affected by cis-Pt. Gamma-glutamyltransferase activity was lowered by as much as 30% in cis-Pt-treated rats when compared to controls, but there was no effect of copper deficiency. Alkaline phosphatase and neutral endopeptidase 24.11 activities were significantly lower in microvilli of cis-Pt-treated rats than in those not treated.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effect of copper deficiency and cis-diamminedichloroplatinum (II) treatment on the activities of renal microvillar enzymes in rats. 198 71

A. niger LCF 9 synthesizes a new aspergillopeptidase of potential interest in therapeutics. The properties and operating range of the enzyme were determined. It is a semi-alkaline aspergillopeptidase (EC 3.4.23.4) with one endopeptidase activity. Its pI is 4.10, its molecular weight is 21000 Da and its A1%(1 cm) at 280 nm is 9.75. It rapidly hydrolyzes casein and hemoglobin. Its optimal pH is 7.8 and optimal temperature is 45 degrees C. It is thermally labile above 40 degrees C but can be stabilized by adding calcium ions. It is inhibited by phenylmethylsulfonyl fluoride (PMSF), by ethylenediaminetetraacetic acid (EDTA) and by certain metals ions, e.g. copper, manganese and cobalt ions. It has no dipeptidase or tripeptidase activity and its esterase activity is weak. It has a high collagenase activity and is to our knowledge the only aspergillopeptidase that is active towards benzoyl-arginine p-nitroanilide (BAPNA).
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PMID:Properties of a new alkaline proteinase from Aspergillus niger. 269 84

Acid proteinase activity is associated with the major surface glycoprotein (gp63) of both extracellular promastigotes and intracellular amastigotes of the parasitic protozoan, Leishmania mexicana. The enzyme purified by monoclonal affinity chromatography from promastigotes is strongly inhibited by metal ion chelators, which is reversible by the addition of Zn(II). This proteinase loses its activity after dialysis against 1,10-phenanthroline. The apoenzyme thus prepared is reactivated substantially by Zn(II) and partially by Cu(II), Cd(II), Co(II), or Ni(II). From the recently published structure of the gene encoding gp63, we identify hitherto unrecognized sequences, which can be aligned to the consensus zinc-binding sites of other known metalloproteinases. Anti-gp63 polyclonal antibodies, but not the monoclonals, precipitate similar molecules from amastigotes. These molecules differ slightly from gp63 in electrophoretic mobility but have similar endopeptidase activity. Phagolysosomal degradation by macrophages of proteins entrapped in liposomes is prevented by coating them with native gp63. This protection is lost with heat denaturation of gp63 to kill its enzymatic activity. The proteolytic activity of the metalloenzyme on the surface of these parasites may thus protect their membrane from cytolytic damages during their survival, differentiation, and multiplication in the phagolysosomes of macrophages.
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PMID:Surface acid proteinase (gp63) of Leishmania mexicana. A metalloenzyme capable of protecting liposome-encapsulated proteins from phagolysosomal degradation by macrophages. 270 73

We present evidence that enzyme activity hydrolyzing Succinoyl trialanine paranitroanilide (Suc(Ala)3NA) expressed by Human Skin Fibroblasts (HSF) in culture could be attributed to the concerted action of an endopeptidase and an aminopeptidase(s). Both endopeptidase and aminopeptidase activities were strongly inhibited by metal chelating agents and Copper and Zinc ions but were insensitive to Tissue Inhibitor of Metallo Proteases (TIMP). These protease activities coeluted on ion exchange chromatography (DEAE Tris acryl M) and were further separated by high-performance liquid chromatography HPLC (TSK 3000 SW). The endopeptidase activity, designated as HSF E1, was eluted at the position corresponding to an Mr equal to 94,000. It has only a limited elastinolytic potential as evaluated on 3H insoluble elastin, but it extensively degrades human skin elastic fibers as directly assessed on human skin tissue sections and further quantitated by automated image analysis. The level of HSF E1 increases with the number of fibroblast passages.
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PMID:Characterization of human skin fibroblasts elastase activity. 304 35

An aminopeptidase has been purified to homogeneity from bovine lens tissue by gel filtration and DEAE-cellulose chromatography. This enzyme has a molecular weight of 96,000 under both native and denaturing conditions. The purified enzyme hydrolyzed a variety of synthetic substrates as well as di-, tri-, and higher molecular weight peptides. Significantly this enzyme is capable of hydrolyzing arginine, lysine, and proline aminoacyl bonds. The pH optimum for activity and stability was 6.0. Both a reduced sulfhydryl group and a divalent metal ion are essential for activity. The native enzyme contains 1.6 mol of zinc and 1.0 mol of copper/mol of enzyme. No activation was seen upon incubation with either magnesium or manganese; however, heavy metal ions were inhibitory. Bestatin and puromycin were effective inhibitors and no endopeptidase activity could be detected in the purified preparation. This enzyme is clearly distinct from the lens leucine aminopeptidase, but rather, is identical to a cytosolic aminopeptidase III isolated from other tissues. Evidence is presented which argues that this enzyme may be the major lens aminopeptidase under in vivo conditions.
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PMID:Isolation and characterization of a new aminopeptidase from bovine lens. 308 20

A peptidase that inactivated neurotensin by cleaving the peptide at the Pro10-Tyr11 bond, generating the biologically inactive fragments neurotensin(1-10) and neurotensin(11-13) was purified from whole rat ileum homogenate. The purified enzyme behaved as a 70-75-kDa monomer as determined by SDS-PAGE analysis in reducing or non-reducing conditions and gel permeation on Ultrogel AcA34. The peptidase was insensitive to thiol-blocking agents and acidic and serine protease inhibitors but could be strongly inhibited by 1,10-phenanthroline, EDTA, dithiothreitol and heavy metal ions such as zinc, copper and cobalt. Zinc was the only divalent cation able potently to reactivate the apoenzyme. This enzyme could be distinguished from endopeptidases EC 3.4.24.15 and EC 3.4.24.11, angiotensin-converting enzyme, proline endopeptidase, aminopeptidase and pyroglutamyl-peptide hydrolase since it was not affected by micromolar concentrations of their specific inhibitors. The peptidase displayed a high affinity for neurotensin (1.6 microM). Studies concerning the specificity of the enzyme towards the sequence of neurotensin established the following. (a) Neurotensin(9-13) was the shortest partial sequence that fully inhibited tritiated neurotensin degradation; shortening the C-terminal part of the neurotensin molecule led to inactive fragments. (b) Amidation of the C-terminal end of the peptide did not prevent the recognition by the peptidase. (c) There existed a strong stereospecificity of the peptidase for the residues in positions 8, 9 and 11 of the neurotensin molecule. (d) Pro-Xaa dipeptides (where Xaa represented aromatic or hydrophobic residues) were the most potent inhibitors of tritiated neurotensin degradation while all the Xaa-Pro dipeptides tested were totally ineffective. (e) The neurotensin-related peptides: neuromedin N, xenopsin and [Lys8-Asn9]neurotensin(8-13), as well as angiotensins I and II and dynorphins(1-8) and (1-13) were as potent as neurotensin in inhibiting [3H]neurotensin hydrolysis.
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PMID:Peripheral inactivation of neurotensin. Isolation and characterization of a metallopeptidase from rat ileum. 340 80


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