Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.23 (MMP)
 4,246 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A high quality solution structure of the matrix metalloproteinase inhibitory N-terminal domain of recombinant human tissue inhibitor of metalloproteinases-1 (N-TIMP-1) has been determined. For the rigidly packed residues, the average RMSD to the mean structure is 0. 57 A for the backbone atoms and 1.00 A for all heavy atoms. Comparison of the solution structure of free N-TIMP-1 with the crystal structure of TIMP-1 bound to the catalytic domain of MMP-3 ( Gomis-R]uth et al., 1997 ) shows that the structural core of the beta barrel flanked by helices is nearly unchanged by the association with MMP-3, evident from a backbone RMSD of 1.15 A. However, clear differences in the conformation of the MMP-binding ridge of free and MMP-bound TIMP-1 suggest induced fit throughout the ridge. The MMP-dependent conformational changes in the ridge include a dramatic bending of AB loop residues Glu28 through Leu34, moderate hinge bending of the CD-loop about residues Ala65 and Cys70, and modest bending of the Cys1 through Pro6 segment. A large number of interresidue Nuclear Overhauser enhancements (NOEs) augmented by stereospecific assignments, torsion restraints, and dipolar couplings (an average of 18 non-trivial restraints per residue) engender confidence in these structural inferences. A tight cluster of three lysine residues and one arginine residue atop beta-strands A and B, and identical among TIMP sequences, form the heart of a highly conserved electropositive patch that may interact with anionic components of the extracellular matrix.
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PMID:NMR structure of tissue inhibitor of metalloproteinases-1 implicates localized induced fit in recognition of matrix metalloproteinases. 1062 24

Wound extracellular matrix is a key regulator of cell adhesion, migration, proliferation, and differentiation during cutaneous repair. The amount and organization of normal wound extracellular matrix are determined by a dynamic balance among overall matrix synthesis, deposition, and degradation. Matrix metalloproteinases (MMPs) are one family of structurally related enzymes that have the collective ability to degrade nearly all extracellular matrix components. The MMPs are broadly categorized into collagenases, gelatinases, stromelysins, and membrane-type MMPs by their substrate specificity. The aim of this study was to characterize the temporal changes in mRNA profiles for rat collagenase [matrix metalloproteinase-1 (MMP-1)], gelatinase A (MMP-2), matrilysin (MMP-7), gelatinase B (MMP-9), and membrane type 1-MMP (MT1-MMP), as well as tissue inhibitor of metalloproteinases-1 (TIMP-1), TIMP-2, and TIMP-3 during the inflammatory, granulation, and early remodeling phases of excisional skin repair. Eight full-thickness skin wounds were made on the backs of each rat (7-mm2 wounds; 16 rats; n = 128 wounds). Two animals at a time were reanesthetized, and all eight wounds on each animal were excised at 12 and 24 hours and at 2, 3, 5, 7, 10, and 14 days after injury. Six wounds from each animal were excised for RNA isolation, whereas two wounds were excised for histology. Controls consisted of nonwounded skin from identical locations in four animals. Total RNA from each time point was isolated and relative mRNA quantitation performed by using reduced-cycle reverse transcription-polymerase chain reaction. Correct polymerase chain reaction product amplification was confirmed by probing the blotted polymerase chain reaction product with a 32P-labeled oligonucleotide specific for a given MMP or TIMP. We demonstrated that the majority of MMP and TIMP mRNA induction and peak expression coincided temporally with the well-characterized inflammatory and granulation stages of repair. In conclusion, there is a distinct pattern of MMP and TIMP expression during normal excisional wound repair.
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PMID:Differential expression of matrix metalloproteinases and their tissue-derived inhibitors in cutaneous wound repair. 1088 58

On the cell surface, the 59-kDa membrane type 1-matrix metalloproteinase (MT1-MMP) activates the 72-kDa progelatinase A (MMP-2) after binding the tissue inhibitor of metalloproteinases (TIMP)-2. A 44-kDa remnant of MT1-MMP, with an N terminus at Gly(285), is also present on the cell after autolytic shedding of the catalytic domain from the hemopexin carboxyl (C) domain, but its role in gelatinase A activation is unknown. We investigated intermolecular interactions in the gelatinase A activation complex using recombinant proteins, domains, and peptides, yeast two-hybrid analysis, solid- and solution-phase assays, cell culture, and immunocytochemistry. A strong interaction between the TIMP-2 C domain (Glu(153)-Pro(221)) and the gelatinase A hemopexin C domain (Gly(446)-Cys(660)) was demonstrated by the yeast two-hybrid system. Epitope masking studies showed that the anionic TIMP-2 C tail lost immunoreactivity after binding, indicating that the tail was buried in the complex. Using recombinant MT1-MMP hemopexin C domain (Gly(285)-Cys(508)), no direct role for the 44-kDa form of MT1-MMP in cell surface activation of progelatinase A was found. Exogenous hemopexin C domain of gelatinase A, but not that of MT1-MMP, blocked the cleavage of the 68-kDa gelatinase A activation intermediate to the fully active 66-kDa enzyme by concanavalin A-stimulated cells. The MT1-MMP hemopexin C domain did not form homodimers nor did it bind the gelatinase A hemopexin C domain, the C tail of TIMP-2, or full-length TIMP-2. Hence, the ectodomain of the remnant 44-kDa form of MT1-MMP appears to play little if any role in the activation of gelatinase A favoring the hypothesis that it accumulates on the cell surface as an inactive, stable degradation product.
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PMID:Domain interactions in the gelatinase A.TIMP-2.MT1-MMP activation complex. The ectodomain of the 44-kDa form of membrane type-1 matrix metalloproteinase does not modulate gelatinase A activation. 1099 43

Wound healing is a complex process involving the interactions of many different cell types, matrix components and biological factors, including proteinases and cytokines. This study compared the levels of proteinases (matrix metalloproteinases and plasminogen activators), proteinase inhibitors (tissue inhibitors of metalloproteinases and plasminogen activator inhibitors), inflammatory cytokines and growth factors in acute wound fluid samples collected from the surgical drains of elective breast (n = 24) and colorectal (n = 26) patients on the first postoperative day. Gelatin zymography was used to determine matrix metalloproteinase-2 and -9 levels, quenched fluorescence substrate hydrolysis was applied for total MMP activity and enzyme-linked immunoassays were used to quantitate other factors. Colorectal wound fluid samples showed significantly (p < 0.05) greater levels of the matrix metalloproteinases (MMP-1, 2, 3, and 9), tissue inhibitor of metalloproteinases-1, urokinase plasminogen activator receptor and the inflammatory cytokines (interleukin-1beta, -6, and tumor necrosis factor-alpha); e.g., matrix metalloproteinase-3 colon; median 275 (range 11-2.530) ng/ml; breast; 530-400. However, tissue plasminogen activator and growth factor levels (epidermal growth factor, platelet-derived growth factor, basic fibroblast growth factor, transforming growth factor-beta1) were significantly greater in breast samples; e.g., epidermal growth factor breast 468 (103-1, 444) pg/ml; colon 57(1-573). There was no difference in the levels of urokinase type plasminogen activator, plasminogen activator inhibitor-1 and -2, tissue inhibitor of metalloproteinases -2 or vascular endothelial growth factor. Acute wound fluid from different surgical wounds showed different profiles of proteinases, proteinase inhibitors, and cytokines. This may lead to differences in the rate of tissue remodeling and therefore healing in these two wounds in vivo.
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PMID:Proteinases, their inhibitors, and cytokine profiles in acute wound fluid. 1111 51

Progressive renal disease as a result of renal fibrosis is caused in part by an impairment of the proteolytic machinery that normally regulates matrix turnover. The goal of the present study was to determine whether genetic deficiency of tissue inhibitor of metalloproteinases-1 (TIMP-1) could attenuate interstitial fibrosis caused by unilateral ureteral obstruction (UUO). Groups of wild-type (Timp-1) mice and TIMP-1-deficient (timp-1) mice were killed after 3 and 14 d of UUO or sham operation. Timp-1 mRNA levels were significantly increased 37- and 19-fold in the wild-type mice 3 and 14 d, respectively, after UUO operation. Matrix metalloproteinase-9 (MMP-9) activity fell in all UUO groups but remained significantly higher in the timp-1 group compared with the Timp-1 group. The degree of interstitial fibrosis (kidney collagen content and percentage of tubulointerstitial area stained with picrosirius red and collagen III) was significantly increased 14 d after UUO operation, but there was no difference between the Timp-1 and timp-1 groups. Many features of the fibrogenic response were similar between the Timp-1 and timp-1 groups, including the number of myofibroblasts and the induction of genes encoding procollagen III, fibronectin, and transforming growth factor-beta. After UUO operation, renal mRNA levels for Timp-3 and plasminogen activator inhibitor-1 were significantly higher in the TIMP-1-deficient mice. The results of this study show that elimination of TIMP-1 alone does not alter the severity of interstitial fibrosis. These findings may be due to compensation by other protease inhibitors such as TIMP-2, TIMP-3, and/or plasminogen activator inhibitor-1 or to the possibility that inhibition of intrinsic MMP activity does not constitute a profibrogenic event in the kidney.
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PMID:TIMP-1 deficiency does not attenuate interstitial fibrosis in obstructive nephropathy. 1127 35

Gelatinase A and B (MMP-2 and MMP-9) are secreted by cytotrophoblast (CTB); these enzymes digest the major constituents of the endometrial extracellular matrices (ECM). Direct evidence links the expression of MMPs to the metastatic phenotype of tumour cells and tissue inhibitor of metalloproteinases (TIMP) to the inhibition of metastatisation. Gelatinase B (MMP-9, and no other MMP) has been shown in vitro to mediate CTB invasion. ECM components are known to influence adhesion, spreading, migration and differentiation of cells through specific cell surface receptors called integrins. While CTB migrate from the villous into the decidua they modulate their integrin repertoire, secrete MMP-9 and acquire the capacity to digest their environment. Although CTB behave like metastatic cells, in vivo they are only transiently invasive (first trimester) and their invasion is essentially limited to the endometrium and to the proximal myometrium. This temporal and spatial regulation seems to be mediated in a paracrine way by uterine factors and in an autocrine way by trophoblastic factors. We investigated the effects of endometrial regulators such as leukaemia inhibitory factor (LIF), tumour necrosis factor (TNF), transforming growth factor beta (TGFb), interleukin-1 and 6 (IL-1, IL-6) and insulin-like growth factor binding protein-1 (IGFBP-1) as well as trophoblastic factors such as hCG and leptin. All these factors markedly influenced the secretion and/or activation of MMP-2 and MMP-9. Most cytokines influence cell behaviour by modulating phosphorylation of transcription factors. Among these we identified two oncogene products (Jun and Fos) which were activated by TNF or phorbol esters and which promoted the synthesis of MMP-9. We conclude that decidual and trophoblastic products are autocrine or paracrine regulators of trophoblastic invasion of the endometrium and that some of these products act by activating the transcription of early response genes such as transcription factors.
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PMID:Endocrine, paracrine and autocrine regulation of trophoblastic metalloproteinases. 1175 1

Adult angiogenesis, associated with pathologic conditions, is often accompanied by the formation of a fibrinous exudate. This temporary matrix consists mainly of fibrin but is intermingled with plasma proteins and collagen fibers. The formation of capillary structures in a fibrinous matrix in vivo was mimicked by an in vitro model, in which human microvascular endothelial cells (hMVECs) seeded on top of a fibrin-10% collagen matrix form capillarylike tubular structures after stimulation with basic fibroblast growth factor/tumor necrosis factor alpha (bFGF/TNF-alpha) or vascular endothelial growth factor (VEGF)/TNF-alpha. In the fibrin-collagen matrix the metalloproteinase inhibitor BB94 inhibited tubule formation by 70% to 80%. Simultaneous inhibition of plasmin and metalloproteinases by aprotinin and BB94 caused a nearly complete inhibition of tubule formation. Adenoviral transduction of tissue inhibitor of metalloproteinases 1 (TIMP-1) and TIMP-3 into endothelial cells revealed that TIMP-3 markedly inhibited angiogenesis, whereas TIMP-1 had only a minor effect. Immunohistochemical analysis showed the presence of matrix metalloproteinase 1 (MMP-1), MMP-2, and membrane-type 1 (MT1)-MMP, whereas MMP-9 was absent. The endothelial production of these MMPs was confirmed by antigen assays and real-time polymerase chain reaction (PCR). MT1-MMP mRNA was markedly increased in endothelial cells under conditions that induced tubular structures. The presence of MMP-1, MMP-2, and MT1-MMP was also demonstrated in vivo in the newly formed vessels of a recanalized arterial mural thrombus. These data suggest that MMPs, in particular MT-MMPs, play a pivotal role in the formation of capillarylike tubular structures in a collagen-containing fibrin matrix in vitro and may be involved in angiogenesis in a fibrinous exudate in vivo.
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PMID:Membrane-type matrix metalloproteinase-mediated angiogenesis in a fibrin-collagen matrix. 1239 8

The high-affinity inhibition of stromelysin 1 (MMP-3) by tissue inhibitor of metalloproteinases 1 (TIMP-1) helps control tissue remodeling and tumor development. The interaction of N-TIMP-1 with the catalytic domain of MMP-3 has been investigated by titration calorimetry and 15N NMR. Their unfavorable enthalpy of binding of +6.5 kcal mol(-1) is unusual among protein-protein associations, deviates from structure-based prediction, and is compensated by a net entropy increase providing at least 18 kcal mol(-1) of favorable free energy of binding at a 1M reference state. The small heat capacity of binding agrees well with the heat capacity predicted from 65% of the surface buried on binding being polar, and suggests that the hydrophobic effect can account for only part of the entropy of binding. Using NMR, binding-induced changes in the backbone of N-TIMP-1 were checked as one possible source of conformational entropy changes. MMP binding slightly increases rigidity in some contact sites in TIMP-1 but increases mobility remotely in the otherwise rigid beta-barrel core of N-TIMP-1, increasing 15N relaxation evidence of pico- to nanosecond and micro- to millisecond fluctuations of beta-strands A-F. Residual dipolar couplings suggest dynamic deviations from X-ray coordinates of the complex. These suggest that the beta-barrel has small backbone conformational fluctuations, while segments of strands betaB, betaE and betaF might experience fluctuations only in their backbone environment. This is a distinctive example of affinity between two well-structured proteins being enhanced by increased conformational entropy in the reservoir of a folding core.
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PMID:Increased backbone mobility in beta-barrel enhances entropy gain driving binding of N-TIMP-1 to MMP-3. 1263 64

Membrane type 1-matrix metalloproteinase (MT1-MMP) is a zinc-dependent, membrane-associated endoproteinase of the metzincin family. The enzyme regulates extracellular matrix remodeling and is capable of cleaving a wide variety of transmembrane proteins. The enzymatic activity of MT1-MMP is regulated by endogenous inhibitors, the tissue inhibitor of metalloproteinases (TIMP). To date, four variants of mammalian TIMP have been identified. Whereas TIMP-2-4 are potent inhibitors against MT1-MMP, TIMP-1 displays negligible inhibitory activity against the enzyme. The rationale for such selectivity is hitherto unknown. Here we identify the surface epitopes that render TIMP-1 inactive against MT1-MMP. We show that TIMP-1 can be transformed into an active inhibitor against MT1-MMP by the mutation of a single residue, namely threonine 98 to leucine (T98L). The resultant mutant displayed inhibitory characteristics of a typical slow, tight binding inhibitor. The potency of the mutant could be further enhanced by the introduction of valine 4 to alanine (V4A) and proline 6 to valine (P6V) mutations. Indeed, the inhibitory profile of the triple mutant (V4A/P6V/T98L) is indistinguishable from those of other TIMPs. Our findings suggest that threonine 98 is critical in initiating MMP binding and complex stabilization. Our findings also provide a potential mechanistic explanation for MMP-TIMP selectivity.
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PMID:Unveiling the surface epitopes that render tissue inhibitor of metalloproteinase-1 inactive against membrane type 1-matrix metalloproteinase. 1286 73

The matrix metalloproteinases (MMPs) are zinc dependent endopeptidases known for their ability to cleave one or several extracellular matrix (ECM) constituents, as well as non-matrix proteins. They comprise a large family of proteinases that share common structural and functional elements and are products of different genes. All members of this family contain a signal peptide, a propeptide and a catalytic domain. The catalytic domain contains two zinc ions and at least one calcium ion coordinated to various residues. All MMPs, with the exception matrilysin, have a hemopexin/vitronectin-like domain that is connected to the catalytic domain by a hinge or linker region. The hemopexin-like domain influences tissue inhibitor of metalloproteinases (TIMP) binding, the binding of certain substrates, membrane activation, and some proteolytic activities. It has been proposed that the origin of MMPs could be traced to before the emergence of vertebrates from invertebrates. It appears conceivable that the domain assemblies occurred at an early stage of the diversification of different MMPs and that they progressed through the evolutionary process independent of one another, and perhaps parallel to each other.
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PMID:Structure and evolutionary aspects of matrix metalloproteinases: a brief overview. 1461 53


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