Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:3.4.24.11 (CD10)
9,792 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

X-linked hypophosphatemia (XLH) is caused by inactivating mutations of Phex, a phosphate-regulating endopeptidase. Further advances in our knowledge of the pathogenesis of XLH require identification of the biological function of Phex and its physiologically relevant substrates. We evaluated several potential substrates using mouse recombinant wild-type Phex proteins (rPhex-WT) and inactive mutant Phex proteins (rPhex-3'M) lacking the COOH-terminal catalytic domain as controls. By Western blot analysis, we demonstrated that Phex is a membrane-bound 100-kDa glycosylated monomer. Neither casein, a substrate for the related endopeptidase thermolysin, human stanniocalcin 1 (hSTC-1), an osteoblast-derived phosphate-regulating factor, nor FGF-23 peptide (amino acid 172-186), comprising the region mutated in autosomal dominant hypophosphatemia, was cleaved by rPhex-WT. In addition, membranes expressing rPhex-WT, rPhex-3'M, and the empty vector hydrolyzed parathyroid hormone-(1-34), indicating the lack of Phex-specific cleavage of parathyroid hormone. In contrast, rPhex-WT did display an EDTA-dependent cleavage of the neutral endopeptidase substrate [Leu]enkephalin. Further studies with wild-type and mutant rPhex proteins should permit the identification of physiologically relevant substrates involved in the pathogenesis of XLH.
...
PMID:Analysis of recombinant Phex: an endopeptidase in search of a substrate. 1155 62

A serine endopeptidase with a molecular mass of 25 kDa has been purified from the culture filtrate of Trichoderma viride to electrophoretic homogeneity. The isoelectric point was determined at 7.3. Two carboxyl sites at Arg22 and Lys29 of the oxidized insulin B-chain were cleaved, and peptidyl-p-nitroanilide substrates with Lys or Arg at the P1 position were also hydrolyzed by the enzyme. These results suggest that the specificity of T. viride protease is similar to that of trypsin. However, the hydrolytic activity toward casein of T. viride protease was less than that of porcine trypsin. The amino-terminal sequence of the enzyme protein is similar to that of bovine trypsin. It seems that the trypsin of T. viride is a protease which is promising for the substitution of animal trypsin in the food industry and in medicine at this stage.
...
PMID:Isolation and characterization of a trypsin-like protease from Trichoderma viride. 1172 35

A neutral activity of Boophilus microplus in the intestine was identified by electrophoresis in polyacrilamide gel copolymerized with gelatin. The maximum of activity was attained at pH 6.0. The highest specific activity at that pH was obtained with casein substrate. The disappearance of this activity was observed in both substrates after the addition of phenylmethylsulphonyl fluoride in the reaction mixtures. It was very interesting to find out an endopeptidase activity with these characteristics in the intestine, in spite of the fact that the digestive activity in ticks is intracellular at very acid pH, which does not occur in other insects.
...
PMID:[Identification of a neutral protease in the intestine of Boophilus microplus with electrophoresis in polyacrylamide gels copolymerized with gelatin]. 1182 17

A glutamyl proteinase was partially purified from Percoll gradient-purified spinach (Spinacia oleracea) chloroplast preparations and appeared to be predominantly localized in the chloroplast stroma. The enzyme degraded casein, but of the 11 synthetic endopeptidase substrates tested, only benzyloxycarbonyl-leucine-leucine-glutamic acid-[beta]-napthylamide was hydrolyzed at measurable rates. In addition, the enzyme cleaved the oxidized [beta]-chain of insulin after a glutamic acid residue. There was no evidence that native ribulose-1,5-bisphosphate carboxylase/oxygenase was cleaved by this proteinase. The apparent Km for benzyloxycarbonyl-leucine-leucine-glutamic acid-[beta]NA at the pH optimum of 8.0 was about 1 mM. Cl-ions were required for both activity and stability. Of the proteinase inhibitors covering all four classes of the endopeptidases, only 4-(2-aminoethyl)-benzenesulfonyl-fluoride HCl and L-1-chloro-3-[4-tosylamido]-4-phenyl-2-butanone significantly inhibited the proteinase. The partially purified enzyme had a molecular weight of about 350,000 to 380,000, based on size-exclusion chromatography. The enzyme has both similar and distinctive properties to those of the bacterial glutamyl proteinases. To our knowledge, this is the first description of a plant glutamyl proteinase found predominantly or exclusively in the chloroplast.
...
PMID:A Plant Chloroplast Glutamyl Proteinase. 1222 39

Succinyl-Leu-Leu-Val-Tyr-7-amido-4-methylcoumarin (Suc-LLVY-AMC), a fluorogenic endopeptidase substrate, is used to detect 20 S proteasomal activity from Archaea to mammals. An o-phenanthroline-sensitive Suc-LLVY-AMC hydrolyzing activity was detected in Escherichia coli although it lacks 20 S proteasomes. We identified PepN, previously characterized as the sole alanine aminopeptidase in E. coli, to be responsible for the hydrolysis of Suc-LLVY-AMC. PepN is an aminoendopeptidase. First, extracts from an ethyl methanesulfonate-derived PepN mutant, 9218, did not cleave Suc-LLVY-AMC and L-Ala-para-nitroanilide (pNA). Second, biochemically purified PepN cleaves a wide variety of both aminopeptidase and endopeptidase substrates, and L-Ala-pNA is cleaved more efficiently than other substrates. Studies with bestatin, an aminopeptidase-specific inhibitor, suggest differences in the mechanisms of cleavage of aminopeptidase and endopeptidase substrates. Third, PepN hydrolyzes whole proteins, casein and albumin. Finally, an E. coli strain with a targeted deletion in PepN also lacks the ability to cleave Suc-LLVY-AMC and L-Ala-pNA, and expression of wild type PepN in this mutant rescues both activities. In addition, we identified a low molecular weight Suc-LLVY-AMC-cleaving peptidase in Mycobacterium smegmatis, a eubacteria harboring 20 S proteasomes, to be an aminopeptidase homologous to E. coli PepN, by mass spectrometry analysis. "Sequence-based homologues" of PepN include well characterized aminopeptidases, e.g. Tricorn interacting factors F2 and F3 in Archaea and puromycin-sensitive aminopeptidase in mammals. However, our results suggest that eubacterial PepN and its homologues displaying aminoendopeptidase activities may be "functionally similar" to enzymes important in downstream processing of proteins in the cytosol: Tricorn-F1-F2-F3 complex in Archaea and TPPII/Multicorn in eukaryotes.
...
PMID:PepN, the major Suc-LLVY-AMC-hydrolyzing enzyme in Escherichia coli, displays functional similarity with downstream processing enzymes in Archaea and eukarya. Implications in cytosolic protein degradation. 1248 50

Peptides derived from hydrolysis of alpha(S1)-casein(f1-9) [alpha(S1)-CN(f1-9)] and beta-CN(f193-209) with cell extracts of Lactobacillus helveticus CNRZ32 and single-peptidase mutants (Delta pepC, Delta pepE, Delta pepN, Delta pepO, and Delta pepX) were isolated by using reverse-phase high-performance liquid chromatography and were characterized by mass spectrometry. The peptides identified suggest that there was activity of an endopeptidase, distinct from previously identified endopeptidases (PepE and PepO), with specificity for peptide bonds C terminal to Pro residues. Identification of hydrolysis products derived from a carboxyl-blocked form of beta-CN(f193-209) confirmed that the peptides were derived from the activity of an endopeptidase.
...
PMID:Hydrolysis of casein-derived peptides alpha(S1)-casein(f1-9) and beta-casein(f193-209) by Lactobacillus helveticus peptidase deletion mutants indicates the presence of a previously undetected endopeptidase. 1257 Oct 58

The degradation of cellular proteins by proteasomes generates peptides 2-24 residues long, which are hydrolyzed rapidly to amino acids. To define the final steps in this pathway and the responsible peptidases, we fractionated by size the peptides generated by proteasomes from beta-[14C]casein and studied in HeLa cell extracts the degradation of the 9-17 residue fraction and also of synthetic deca- and dodecapeptide libraries, because peptides of this size serve as precursors to MHC class I antigenic peptides. Their hydrolysis was followed by measuring the generation of smaller peptides or of new amino groups using fluorescamine. The 14C-labeled peptides released by 20 S proteasomes could not be degraded further by proteasomes. However, their degradation in the extracts and that of the peptide libraries was completely blocked by o-phenanthroline and thus required metallopeptidases. One such endopeptidase, thimet oligopeptidase (TOP), which was recently shown to degrade many antigenic precursors in the cytosol, was found to play a major role in degrading proteasome products. Inhibition or immunodepletion of TOP decreased their degradation and that of the peptide libraries by 30-50%. Pure TOP failed to degrade proteasome products 18-24 residues long but degraded the 9-17 residue fraction to peptides of 6-9 residues. When aminopeptidases in the cell extract were inhibited with bestatin, the 9-17 residue proteasome products were also converted to peptides of 6-9 residues, instead of smaller products. Accordingly, the cytosolic aminopeptidase, leucine aminopeptidase, could not degrade the 9-17 residue fraction but hydrolyzed the peptides generated by TOP to smaller products, recapitulating the process in cell extracts. Inactivation of both TOP and aminopeptidases blocked the degradation of proteasome products and peptide libraries nearly completely. Thus, degradation of most 9-17 residue proteasome products is initiated by endoproteolytic cleavages, primarily by TOP, and the resulting 6-9 residue fragments are further digested to amino acids by aminopeptidases.
...
PMID:Pathway for degradation of peptides generated by proteasomes: a key role for thimet oligopeptidase and other metallopeptidases. 1532 61

The proteolytic system of Bifidobacterium animalis subsp. lactis was analyzed, and an intracellular endopeptidase (PepO) was identified and characterized. This work reports the first complete cloning, purification, and characterization of a proteolytic enzyme in Bifidobacterium spp. Aminopeptidase activities (general aminopeptidases, proline iminopeptidase, X-prolyl dipeptidylaminopeptidase) found in cell extracts of B. animalis subsp. lactis were higher for cells that had been grown in a milk-based medium than for those grown in MRS. A high specific proline iminopeptidase activity was observed in B. animalis subsp. lactis. Whole cells and cell wall-bound protein fractions showed no caseinolytic activity; however, the combined action of intracellular proteolytic enzymes could hydrolyze casein fractions rapidly. The endopeptidase activity of B. animalis subsp. lactis was examined in more detail, and the gene encoding an endopeptidase O in B. animalis subsp. lactis was cloned and overexpressed in Escherichia coli. The deduced amino acid sequence for B. animalis subsp. lactis PepO indicated that it is a member of the M13 peptidase family of zinc metallopeptidases and displays 67.4% sequence homology with the predicted PepO protein from Bifidobacterium longum. The recombinant enzyme was shown to be a 74-kDa monomer. Activity of B. animalis subsp. lactis PepO was found with oligopeptide substrates of at least 5 amino acid residues, such as met-enkephalin, and with larger substrates, such as the 23-amino-acid peptide alpha s1-casein(f1-23). The predominant peptide bond cleaved by B. animalis subsp. lactis PepO was on the N-terminal side of phenylalanine residues. The enzyme also showed a post-proline secondary cleavage site.
...
PMID:Enzymatic ability of Bifidobacterium animalis subsp. lactis to hydrolyze milk proteins: identification and characterization of endopeptidase O. 1633 35

Beauveria bassiana GK2016 grown in a medium with gelatin as the sole carbon and nitrogen source produced an extracellular protease. The protease production was highest when the fungus was grown on a semiliquid medium and was purified about 18-fold, with a recovery of 21%. The protease molecular weight was estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis to be about 35,000. It had an optimum activity at pH 8.5 and 37 degrees C and was rapidly inactivated at 50 degrees C. Its enzymatic activity was that of an endopeptidase which hydrolyzed elastin, casein, and gelatin but was much less active on bovine serum albumin and collagen. No trypsinlike activity was detected on N-alpha-benzoyl-dl-arginine-p-nitroanilide. It was, however, inhibited by phenylmethylsulfonyl fluoride, indicating that a serine residue is present in the active site. The protease was unaffected by metal-chelating agents, sulfhydryl reagents, trypsin inhibitor, and chymotrypsin inhibitor.
...
PMID:Purification and Properties of an Extracellular Protease Produced by the Entomopathogenic Fungus Beauveria bassiana. 1634 95

During the ripening of Gouda-type cheese, two kinds of endopeptidases were found to participate in the degradation of alphas1-CN(f1-23), a specific product from alphas1-casein hydrolyzed by chymosin. One of the endopeptidases, lactic acid bacteria endopeptidase (LEP-II), which can recognize the size of its substrates, has already been purified and characterized (T. R. Yan, N. Azuma, S. Kaminogawa, and K. Yamauchi, Eur. J. Biochem. 163:259-265, 1987). The other endopeptidase, LEP-I, was purified to homogeneity by conventional chromatographic techniques from Streptococcus cremoris H61. The enzyme appeared to be monomeric, with an apparent molecular weight of 98,000, and its isoelectric point was 5.1. For the hydrolysis of alphas1-CN(f1-23), the enzyme had an optimum pH and temperature of 7.0 to 7.5 and 40 degrees C, respectively. Its activity was inhibited by such chelating agents as EDTA and 1,10-phenanthrolin, and it could be fully reactivated by Mn. Inhibitors specific for serine and thiol proteases had no effect on the protease activity. The enzyme showed a high affinity toward the Glu-Asn peptide bond of alphas1-CN(f1-23) and alphas1-CN(f91-100) but showed no hydrolysis activity toward alphas1-CN(f1-52), alphas1-CN(61-122), alphas1-CN(136-196), alphas1-casein, beta-casein, kappa-casein, alpha-lactalbumin, and beta-lactoglobulin. The K(m) and V(max) of LEP-I for alphas1-CN(f1-23) were 14.2 pM and 139 U, respectively.
...
PMID:Purification and Characterization of a Substrate-Size-Recognizing Metalloendopeptidase from Streptococcus cremoris H61. 1634 50


<< Previous 1 2 3 4 5 6 7 Next >>

---