Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P20366 (substance P)
 21,176 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The main somatostatin-degrading proteases were purified from rat and pig brain homogenates and characterized as thiol- and metal-dependent endoproteases. Two types of proteases with apparent native and subunit molecular masses of 70 kDa and 68 kDa could be differentiated in both species. Beside somatostatin, both hydrolyzed several other neuropeptides with chain lengths between 8 and 30 amino acid residues. Cleavage sites were generally similar or identical, but some clear exceptions were observed for enzymes from both species which could be used to differentiate between the two proteases. The 68-kDa protease cleaved somatostatin at three bonds (Asn5-Phe6, Phe6-Phe7 and Thr10-Phe11) and neurotensin only at the Arg8-Arg9 bond, whereas the 70-kDa protease digested somatostatin at only two bonds (Phe6-Phe7 and Thr10-Phe11) and neurotensin as well as acetylneurotensin-(8-13) additionally (pig protease) or almost exclusively (rat protease) at the Pro10-Tyr11 bond. Relative rates for the digestions of various peptides were, however, more dependent on the species than on the type of protease. Cleavage sites for angiotensin II, bradykinin, dynorphin, gonadoliberin and substance P were, apart from different rates, identical for both proteases. In both species the 68-kDa protease was found to be mainly, but not exclusively, soluble and not membrane-associated, whereas the inverse was detected for the 70-kDa protease. Based on distinct molecular and catalytic properties, the 68-kDa protease is supposed to be congruent with the endopeptidase 24.15 (EC 3.4.24.15), the 70-kDa protease with endopeptidase 24.16 (EC 3.4.24.16, neurotensin-degrading endopeptidase). This investigation demonstrates that both proteases hydrolyze various neuropeptides with similar cleavage sites, but with species-dependent activity. Species-independent distinctions are the exclusive action of endopeptidase 24.16 on acetylneurotensin-(8-13) and liberation of free Phe from somatostatin only by endopeptidase 24.15.
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PMID:Purification of the main somatostatin-degrading proteases from rat and pig brains, their action on other neuropeptides, and their identification as endopeptidases 24.15 and 24.16. 135 47

Neutral endopeptidases EC 3.4.24.11 and EC 3.4.24.15, widely distributed zinc metalloendopeptidases, degrade a number of biologically active peptides including substance P, bradykinin, neurotensin, and luteinizing hormone-releasing hormone. In this study we measured EC 3.4.24.11 and EC 3.4.24.15 activity in alveolar macrophages, key inflammatory cells in the lung that produce and respond to a large number of bioactive substances including chemotactic peptides, with the substrates glutaryl-ala-ala-phe-2-naphthylamide and tertiary butoxycarbonyl-phe-ala-ala-phe-paraaminobenzoate, respectively. We found that specific activity of EC 3.4.24.15, defined as activity inhibited with N-[(1RS)-carboxy-3-phenylpropyl]-ala-ala-phe-paraaminobenzoate+ ++, was significantly higher (p < 0.001) in cells from Sprague-Dawley rats (485 +/- 123 nmol/mg protein.hr) than in cells from Hartley guinea pigs (138 +/- 94 nmol/mg protein.hr), healthy human male smokers (121 +/- 73 nmol/mg protein.hr) and healthy human male nonsmokers (94 +/- 12). In contrast, activity of EC 3.4.24.11, defined as activity inhibited with N-[(1RS)-carboxy-3-phenylpropyl]-phe-paraaminobenzoate, was significantly higher (p < 0.001) in cells from human smokers (689 +/- 167 nmol/mg protein.hr) and nonsmokers (762 +/- 136 nmol/mg protein.hr) than in cells from rats (52 +/- 12 nmol/mg protein.hr) and guinea pigs (34 +/- 14 nmol/mg protein.hr). An additional activity in alveolar macrophages toward tertiary butorycarbonyl-phe-ala-ala-phe-paraaminobenzoate was inhibited with L-3-carboxy-trans-2,3-epoxypropionyl-leucylamido-(4-guanido) butane, a specific inhibitor of cysteine proteinases, a finding of interest because in general enzymes in this class show little activity at neutral pH.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Identification of two zinc metalloendopeptidases in alveolar macrophages of rats, guinea pigs, and human beings. 140 35

Neurotensin (NT) endopeptidase (EC 3.4.24.16) has been purified about 800-fold from pig brain by four sequential chromatographic steps depending on ion-exchange and hydrophobic interactions. Two types of preparation were studied: one from a Triton X-100-solubilized membrane fraction, and the other from the soluble fraction containing 90% or more of the total activity in the homogenate. NT endopeptidase activity was monitored by high-precision liquid chromatography of the two peptide products, characterized as NT-(1-10) and NT-(1-8), resulting from cleavage of the Pro10-Tyr11 and Arg8-Arg9 bonds respectively. As purification proceeded, from both membranes and cytosol, the yield of the two products achieved a constant ratio of 5:1 and this ratio was reproduced in repeated purifications. However, a distinct peptidase which hydrolysed exclusively at the Arg8-Arg9 bond was partially resolved from NT endopeptidase by chromatography on hydroxyapatite, and this activity was further purified and assigned to endopeptidase-24.15 (EC 3.4.24.15). SDS/PAGE of both preparations of neurotensin endopeptidase revealed a major band of apparent Mr 75000, and treatment of the membrane-associated form with N-Glycanase gave no evidence that the enzyme was a glycoprotein. The membrane-associated and cytosol forms of NT endopeptidase activities, monitored for both NT-(1-10) and NT-(1-8) products, were compared in their responses to 1,10-phenanthroline, EDTA, dithiothreitol (DTT) and some synthetic site-directed inhibitors of endopeptidase-24.15 or peptidyl dipeptidase A. The effects revealed no significant differences between the two preparations, nor did the reagents discriminate between the activities generating the two NT fragments. The partially purified form of endopeptidase-24.15 was also included in this comparison: while some responses were similar, this peptidase was distinguishable in its activation by DTT and its relative resistance to inhibition by EDTA. Both forms of NT endopeptidase were found to hydrolyse other substrates, including Boc-Phe-Ala-Ala-Phe-4-aminobenzoate, bradykinin and substance P (these at faster rates than neurotensin), as well as dynorphin A-(1-8) and luliberin. The bonds hydrolysed in these neuropeptides, as well as in angiotensins I and II and alpha-neoendorphin, were defined. These studies confirm that NT endopeptidase is distinct from endopeptidase-24.15. They further show that the former is a soluble enzyme, not an integral membrane protein, that it is not peptide-specific and that it might be more appropriately named. enzyme, not an integral membrane protein, that it is not peptide-specific and
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PMID:Purification and properties of a neurotensin-degrading endopeptidase from pig brain. 190 21

Endopeptidase 24.15 (EP 24.15; EC 3.4.24.15), a zinc-metalloendopeptidase purified from rat brain and testes and also present in many other tissues, including the lung, degrades substance P, neurotensin, bradykinin, luteinizing hormone-releasing hormone, and some other bioactive peptides. The enzyme, present both as soluble cytoplasmic and membrane-bound forms, also rapidly converts dynorphin, alpha- and beta-neoendorphin, and some other opioid peptides into their respective enkephalins. In this study, a rabbit antibody to EP 24.15 purified from rat testes was used to study distribution of the enzyme in rat trachea, lung tissue, and alveolar macrophages (AMs) by immunohistochemical techniques. We found intense immunoreactivity to EP 24.15 within the cytoplasm of ciliated epithelial cells of tracheobronchial mucosa extending from trachea to terminal bronchioles. In addition, large myelinated paratracheal and peribronchial nerve fibers showed immunoreactivity. Blood vessels and alveolar lining cells were negative. AMs also showed intense diffuse cytoplasmic immunoreactivity. The findings of EP 24.15 immunoreactivity in airway epithelium, AMs, and paratracheal and peribroncheal nerve fibers suggest that the enzyme may modulate the activities of bioactive peptides within the lung.
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PMID:Immunohistochemical localization of endopeptidase 24.15 in rat trachea, lung tissue, and alveolar macrophages. 225 85

We have characterized and compared the substrate specificity of affinity-purified recombinant rat testes endopeptidase EC 3.4.24.15 (EP 24.15) with that reported for the isolated brain enzyme. Of the peptides tested, only bradykinin, dynorphin A1-8, and neurotensin were efficiently cleaved by the recombinant enzyme (kcat/Km = 3.0, 2.8 and 0.5 x 10(5) M-1sec-1, respectively); other peptides considered substrates of EP 24.15 (gonadotropin-releasing hormone, substance P, somatostatin and angiotensin) were not metabolized. The enzyme was inhibited by metal ion chelators and thiol-reactive agents, as well as a specific EP 24.15 inhibitor (N-[1(R,S)-carboxy-3-phenylpropyl]-Ala-Ala-Tyr-p-aminobenzoate), thus confirming the enzyme as a thiol-dependent metalloendopeptidase. The observed discrepancies in substrate specificity of the recombinant testicular and the isolated brain enzymes may result from tissue-specific forms and/or post-translational modifications of EP 24.15.
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PMID:Substrate specificity differences between recombinant rat testes endopeptidase EC 3.4.24.15 and the native brain enzyme. 773 70

The action of neuropeptides at the synapse is terminated through enzymatic degradation by membrane-bound proteases. We defined and purified membrane-bound proteases functioning at the initial stage of degradation of four neuropeptides. 1. Substance P-degrading endopeptidases isolated from the rat brain and pig striatum showed similar properties to those of endopeptidase-24.16 (neurolysin) except for cleavage sites of substance P. 2. LHRH fragment (1-5)-generating endopeptidases isolated from the neuroblastoma cells and rat brain showed similar properties to those of endopeptidase-24.15 (thimet oligopeptidase). 3. One of two dynorphin-degrading cysteine proteases isolated from neuroblastoma cells showed strict specificity toward the Arg-Arg residues. 4. Endopeptidase-24.11 (neprilysin) isolated from the rat brain was identified as a somatostatin-degrading enzyme.
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PMID:[Membrane-bound proteases involved in neuropeptide degradation in the brain]. 836 28

The recombinant rat testes metallo-endooligopeptidase (EC 3.4.24.15) and the rabbit brain endooligopeptidase A (formerly EC 3.4.22.19) were compared, side-by-side, in view of their striking similarities in both the physicochemical features and the specificities for oligopeptides. Concerning the tissue distribution in rat and rabbit, no relation between the levels of enzyme activity in cytosol and the levels of metallo-endooligopeptidase 24.15 mRNA could be established. The results suggest that the predominant neuropeptide-metabolizing activity attributed to the metallo-endooligopeptidase 24.15 is performed by, at least, two distinct cytosolic enzymes, one predominant in rat testes and the other in rabbit brain and testes, and possibly also in rat brain. Both enzymes are activated by dithiothreitol and irreversibly inhibited by a SH-affinity labeling dynorphin-related compound, but they are not inhibited by EDTA in a concentration dependent manner. Both enzymes exhibit the same specificity toward several bioactive peptides, except for LH-RH and substance P, which are only hydrolysed by the rat testes enzyme. Taken together, these results lead us to conclude that it is unlikely that the recombinant rat testes metallo-endooligopeptidase 24.15 and the rabbit brain endooligopeptidase A are the same molecule although they might belong to the same family of oligopeptidases.
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PMID:Species specificity of thimet oligopeptidase (EC 3.4.24.15). 882 19