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

To elucidate structure-function relationships of stromelysin-3, a putative matrix metalloproteinase originally identified at the tumor-stromal cell interface in breast carcinomas, the human cDNA was expressed in mammalian cells, and its products were isolated and characterized. In stably transfected cells, stromelysin-3 was recovered as a complex mixture of species ranging in size from approximately 20 to 65 kDa. Among these products, a major 45-kDa species with an N terminus of Phe98 and an intact C-terminal domain was identified as a true endopeptidase on the basis of its ability to cleave the bait region of alpha 2-macroglobulin between Phe684 and Tyr685, a site identical to that recognized by stromelysin-1. However, unlike stromelysin-1 or other members of the matrix metalloproteinase family, the mature form of stromelysin-3 was unable to hydrolyze a range of extracellular matrix molecules associated with either the basement membrane or interstitium. To probe for alternate substrates among tumor cell-derived products, purified stromelysin-3 was incubated with [35S]methionine-labeled medium conditioned by the breast cancer cell line, MCF-7. Under these conditions, a single, tumor cell-derived protein was hydrolyzed as assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography. Following anion-exchange chromatography and preparative gel electrophoresis, the stromelysin-3 substrate was identified by N-terminal sequencing as the serine proteinase inhibitor, alpha 1-proteinase inhibitor. Further studies demonstrated that stromelysin-3 rapidly destroyed the antiproteolytic function of alpha 1-proteinase inhibitor by cleaving the antiproteinase at a distinct site between Ala350 and Met351 within the reactive-site loop. Together, these data not only demonstrate that human stromelysin-3 acts as a powerful endopeptidase with a restricted substrate specificity distinct from all other matrix metalloproteinases, but also serve to identify serine proteinase inhibitors as potential physiologic targets at sites of extracellular matrix remodeling.
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PMID:Hydrolytic inactivation of a breast carcinoma cell-derived serpin by human stromelysin-3. 752 94

Gelatinase B (MMP-9), a member of the matrix metalloproteinase family, is a zinc- and calcium-dependent endopeptidase that is known to play a role in tumor cell invasion and in destruction of cartilage in arthritis. It contains a conserved sequence. 400His-(X)3-His-(X)28-Asp-Asp-(X)2-436Gly, the function of which is under investigation. The conserved Asp-432 and Asp-433 residues were individually replaced with Gly; these substitutions reduced the gelatinolytic activity of the enzyme to 23% and 0%, respectively. Replacing Asp-433 with Glu, however, decreased the gelatinolytic activity of the enzyme by 93% and proteolytic activity of the enzyme for the Mca-Pro-Leu-Gly-Leu-Dpa-Ala-Arg-NH2 substrate by 79%. The wild-type and D432G and D433E, mutant enzymes had similar Km values for the synthetic substrate and similar Ki values for the competitive inhibitor, GM6001. The kcat/Km values for D432G and D433E mutant enzymes, however, were reduced by a factor of approximately 4 and their KaCa values were increased by four- and sixfold, respectively. The significance of His-400 in the activity of the enzyme was assessed by replacing this residue with Ala and Phe. Both H400A and H400F mutants were inactive toward gelatin substrate. These data demonstrate that Asp-432, Asp-433, and His-400 residues are important for the activity of gelatinase B. His-400 may act as a zinc-binding ligand similar to the His-197 in interstitial collagenase (MMP-7) and Asp-432 and Asp-433 residues are probably involved in stabilization of the active site of the enzyme. The His-400 and Asp-433 residues are conserved in all members of the MMP family. Therefore, our results are relevant to this group as a whole.
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PMID:Role of the conserved histidine and aspartic acid residues in activity and stabilization of human gelatinase B: an example of matrix metalloproteinases. 856 49

Two series of compounds synthesized as specific matrix metalloproteinase (MMP) inhibitors have been evaluated for their inhibition of non-MMPs. In a series of substituted succinyl hydroxamic acids, some were found to be significant (IC50 < 1 microM) inhibitors of leucine (microsomal) aminopeptidase, neprilysin (3.4.24.11), and thermolysin. Macrocyclic compounds in which the alpha carbon of the succinyl hydroxamate is linked to the side chain of the P2' amino acid were found to be good inhibitors of aminopeptidase, but not of neprilysin or thermolysin. Compounds of neither series were found to be significant inhibitors of angiotensin converting enzyme or carboxypeptidase A.
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PMID:Evaluation of the inhibition of other metalloproteinases by matrix metalloproteinase inhibitors. 1053 76

A novel single polypeptide endopeptidase of 24 kDa (24k-endopeptidase) was purified with a yield of 300-400 microg/L from conditioned medium of a bacterial strain which was identified as a new species in the genus Chryseobacterium Sp. on the basis of its 16S rDNA sequence and DNA:DNA hybridizations. The NH(2)-terminal amino acid sequence (Val-Ala-Thr-Pro-Asn-Leu-Glu-.) was not found in the availabe databases. The 24k-endopeptidase specifically hydrolyzed the Ser(441)-Val(442) peptide bond in human plasmin(ogen), with additional cleavage of the Lys(78)-Val(79) and Pro(447)-Val(448) peptide bonds, and a secondary cleavage at Lys(615)-Val(616). Thereby, plasminogen is converted into an angiostatin-like fragment containing kringles 1-4 (K1-4) and miniplasminogen (kringle 5 and the serine proteinase domain). The purified K1-4 fragment showed a comparable cytotoxicity toward endothelial cells as the elastase-derived K1-3 fragment (12.7% versus 10.6% at a concentration of 10 microg/mL). Plasminogen, bound to monocytoid THP-1 cells, was also cleaved by the 24k-endopeptidase, resulting in generation of an angiostatin-like fragment and in a decreased capacity to generate cell-associated plasmin following activation by urokinase. The 24k-endopeptidase was not efficiently neutralized by specific inhibitors against the serine, cysteine, aspartic, or matrix metalloproteinase classes of enzymes. In human plasma or serum, however, it induced only very limited plasminogen degradation, apparently due to neutralization of its activity by alpha(2)-macroglobulin. Interaction of this novel 24k-endopeptidase with plasminogen thus yields an angiostatin-like fragment and affects plasmin-mediated cellular proteolytic activity.
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PMID:Specific proteolysis of human plasminogen by a 24 kDa endopeptidase from a novel Chryseobacterium Sp. 1063 Oct 10

Metalloproteinases have a critical role in a broad spectrum of cellular processes ranging from the breakdown of extracellular matrix to the processing of signal transduction-related proteins. These hydrolytic functions underlie a variety of mechanisms related to developmental processes as well as disease states. Structural analysis of metalloproteinases from both invertebrate and vertebrate species indicates that these enzymes are highly conserved and arose early during metazoan evolution. In this regard, studies from various laboratories have reported that a number of classes of metalloproteinases are found in hydra, a member of Cnidaria, the second oldest of existing animal phyla. These studies demonstrate that the hydra genome contains at least three classes of metalloproteinases to include members of the 1) astacin class, 2) matrix metalloproteinase class, and 3) neprilysin class. Functional studies indicate that these metalloproteinases play diverse and important roles in hydra morphogenesis and cell differentiation as well as specialized functions in adult polyps. This article will review the structure, expression, and function of these metalloproteinases in hydra.
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PMID:Structure, expression, and developmental function of early divergent forms of metalloproteinases in hydra. 1229 76

Circulating and vascular endothelin-1 (ET-1) levels are elevated in diabetes, but the molecular components of the enzymatic activation of ET-1 in the vasculature remains unknown. Furthermore, the distribution of ET receptors favors a contractile phenotype in African Americans with diabetes. Whether there is any difference in local ET-1 activation in this population is unknown. This study examined the expression and activity of ET converting enzyme-1 subisoforms (ECE-1) in the internal mammary artery specimens obtained from patients undergoing coronary artery bypass grafting. The study groups included African-American (AA) and Caucasian (CA), nondiabetic (ND) and diabetic (D) patients: AAND N = 10, CAND N = 9, AAD N = 9, and CAD N = 11. The expression of ECE-1 a, ECE-1 b and ECE-1c subisoforms was studied by RT-PCR. ECE-1 a was upregulated 2- and 4-fold in the CAD and MD groups, respectively (P < .05). In African-American patient groups, ECE-1 activity (fmol/ mg protein.h) was augmented from 2,804 +/- 185 in nondiabetic tissue samples to 6,857 +/- 393 in the diabetic tissue (P < .05). There was a similar increase in the CAD group, which did not significantly differ from AA diabetics. ECE-1 inhibitors, phosphoramidon and FR-901533, inhibited vascular ECE-1 activity by more than 80%. While neutral endopeptidase (NEP) and matrix metalloproteinase-2 (MMP-2) are able to process big ET-1, inhibitors of NEP (thiorphan) and MMP (batimistat) did not affect ECE-1 activity. In conclusion, the enzymatic pathway essential for generating vascular ET-1 is activated in the vasculature of both AA and CA diabetic patients and this activation is highly specific for ECE-1.
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PMID:Vascular endothelin converting enzyme-1 expression and activity is upregulated in clinical diabetes. 1247 47

The endothelin-converting enzyme (ECE) is the main enzyme responsible for the genesis of the potent pressor peptide endothelin-1 (ET-1). It is suggested that the ECE is pivotal in the genesis of ET-1, considering that the knockout of both genes generates the same lethal developments during the embryonic stage. Several isoforms of the ECE have been disclosed, namely ECE-1, ECE-2, and ECE-3. Within each of the first two groups, several sub-isoforms derived through splicing of single genes have also been identified. In this review, the characteristics of each sub-isoform for ECE-1 and 2 will be discussed. It is important to mention that the ECE is, however, not the sole enzyme involved in the genesis of endothelins. Indeed, other moieties, such as chymase and matrix metalloproteinase II, have been suggested to be involved in the production of ET intermediates, such as ET-1 (1-31) and ET-1 (1-32), respectively. Other enzymes, such as the neutral endopeptidase 24-11, is curiously not only involved in the degradation and inactivation of ET-1, but is also responsible for the final production of the peptide via the hydrolysis of ET-1 (1-31). In this review, we will attempt to summarize, through the above-mentioned characteristics, the current wisdom on the role of these different enzymes in the genesis and termination of effect of the most potent pressor peptide reported to date.
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PMID:Synthesis and degradation of endothelin-1. 1283 62

Membrane type 1-matrix metalloproteinase (MT1-MMP) is an integral type I transmembrane multidomain zinc-dependent endopeptidase involved in extracellular matrix remodelling in physiological as well as pathological processes. MT1-MMP participates in the regulated turnover of various extracellular matrix components as well as the activation of secreted metalloproteinases and the cleavage of various cell membrane components. MT1-MMP expression has been reported to correlate with the malignancy of various tumour types and is thought to be an important mediator of cell migration and invasion. Recently, it has been proposed that internalisation of the enzyme from the cell surface is a major short-term level of MT1-MMP regulation controlling the net amount of active enzyme present at the plasma membrane. In this paper we show that, in HT1080 fibrosarcoma cells, MT1-MMP is internalised from the cell surface and colocalises with various markers of the endocytic compartment. Interestingly, we observed that in these cells, internalisation occurs by a combination of both clathrin-mediated and -independent pathways, most probably involving caveolae. In addition, internalised MT1-MMP is recycled to the cell surface, which could, in addition to downregulation of the enzymatic activity, represent a rapid response mechanism used by the cell for relocalising active MT1-MMP at the leading edge during migration.
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PMID:Membrane type I-matrix metalloproteinase (MT1-MMP) is internalised by two different pathways and is recycled to the cell surface. 1291 89

The cell surface aminopeptidase N (APN/CD13), overexpressed in tumor cells, plays a critical role in angiogenesis. However, potent, selective, and, particularly, noncytotoxic inhibitors ot this protein are lacking, and the present work was undertaken with the aim of developing a new generation of noncytotoxic inhibitors that bind to APN/CD13. In this context, we have synthesized a series of novel flavone-8-acetic acid derivatives. Among the herein described and evaluated compounds, the 2',3-dinitroflavone-8-acetic acid (19b) proved to be the most efficient and exhibited an IC(50) of 25 microM which is 2.5 times higher than that of bestatin (1), the natural known inhibitor of APN/CD13. However, in contrast to bestatin (1), the dinitroflavone 19b did not induce any cytotoxicity to cultured human model cells. The presence of other substituents such as NO(2) or OCH(3) groups at the 3'- or 4'-position of the B phenyl group, or the existence of steric constraints (compounds 24 and 29), did not improve selectivity and potency. The flavone 19b affinity for APN/CD13 is not recovered with other proteases such as matrix metalloproteinase-9 (MMP-9), angiotensin converting enzyme (ACE/CD143), neutral endopeptidase (NEP/CD10), gamma-glutamyl transpeptidase (CD224), or the serine proteases dipeptidyl peptidase IV (DPPIV/CD26) or cathepsin G.
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PMID:Synthesis and biological evaluation of novel flavone-8-acetic acid derivatives as reversible inhibitors of aminopeptidase N/CD13. 1293 Jan 51

Metalloproteases (MPs) are a large and diverse class of enzymes implicated in numerous physiological and pathological processes, including tissue remodeling, peptide hormone processing, and cancer. MPs are tightly regulated by multiple posttranslational mechanisms in vivo, hindering their functional analysis by conventional genomic and proteomic methods. Here we describe a general strategy for creating activity-based proteomic probes for MPs by coupling a zinc-chelating hydroxamate to a benzophenone photocrosslinker, which promote selective binding and modification of MP active sites, respectively. These probes labeled active MPs but not their zymogen or inhibitor-bound counterparts and were used to identify members of this enzyme class up-regulated in invasive cancer cells and to evaluate the selectivity of MP inhibitors in whole proteomes. Interestingly, the matrix metalloproteinase inhibitor GM6001 (ilomastat), which is currently in clinical development, was found to also target the neprilysin, aminopeptidase, and dipeptidylpeptidase clans of MPs. These results demonstrate that MPs can display overlapping inhibitor sensitivities despite lacking sequence homology and stress the need to evaluate MP inhibitors broadly across this enzyme class to develop agents with suitable target selectivities in vivo. Activity-based profiling offers a powerful means for conducting such screens, as this approach can be carried out directly in whole proteomes, thereby facilitating the discovery of disease-associated MPs concurrently with inhibitors that selectively target these proteins.
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PMID:Activity-based probes for the proteomic profiling of metalloproteases. 1522 Apr 80


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