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

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Query: EC:3.4.24.3 (collagenase)
18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Elastin was extracted from human aortic plaque and adjacent grossly normal intima by the following methods: (1) 0.1 N NaOH at 100 degrees C, (2) hot NaOH and 0.2 M EDTA, (3) 5 M guanidine--HCl and collagenase, (4) guanidine--collagenase and dithioerythritol--urea--sodium dodecyl sulfate, (5) guanidine--collagenase and EDTA, (6) 10% NaCl and collagenase, and (7) NaCl--collagenase and EDTA. All elastin samples contained small amounts of carbohydrate and hydroxyproline. The lipid content of non-plaque intimal elastin samples was small (2--3%), whereas it increased to 4--6% in plaque intima. The lipid composition of elastin preparations varied significantly with the extraction procedure. Elastin from plaque intima contained significantly more cholesterol (50--60%) and less triglyceride and phospholipid than elastin of non-plaque intima (30--50% cholesterol). The contents of free and esterified cholesterol were comparable in all preparations. The main phospholipid in all samples was sphingomyelin, which comprised between 50 and 80% of the total phospholipid. Compared with NaOH-purified elastin, the other elastin samples were characterized by an increased phosphatidyl--choline content, while they all contained an almost equal amount of phosphatidylethanolamine. In elastin samples from plaque intima, the polar amino acids were increased, whereas cross-linking amino acids were decreased. The polarity and hydroxyproline content of elastin samples were slightly decreased after treatment with EDTA or dithioerythritol--urea--sodium dodecyl sulfate.
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PMID:Elastin--lipid interaction action in the arterial wall. Part 1. Extraction of elastin from human aortic intima. 46 28

Samples from the ascending aortae from two calves affected by bovine Marfan syndrome were subjected to biochemical analyses of the connective tissue and were compared to age-matched controls. Elastin was extracted from the aortic samples with 5 M guanidine-HCl, bacterial collagenase digestion, and dithiothreitol reduction. Amino acid analysis revealed that desmosine and isodesmosine levels were the same in Marfan calves as in control animals. Gravimetric measurements of elastin, amino acid composition, soluble protein, and uronic acid values also showed no significant difference between Marfan and control tissue. In contrast to elastin, collagen in aortae of Marfan calves was significantly higher than the mean of several controls. These findings, along with other observations of this animal model, support the conclusion that the microscopic and biochemical lesions of aortic elastin in bovine Marfan syndrome likely result from defective microfibrillar metabolism. Absence of cystic medial necrosis in bovine Marfan aortae may explain normal elastin content in the animal model.
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PMID:Normal elastin content of aorta in bovine Marfan syndrome. 142 58

Elastin was purified from baboon aorta using Achromobacter collagenase and its susceptibility to proteolysis by various enzymes was studied. Human leukocyte elastase (HLE) hydrolysed baboon aortic elastin 8 times faster than human cathepsin G. Bovine chymotrypsin had virtually no activity against this substrate. The kinetic constants V and [S50] of aortic elastin hydrolysis by HLE (0.15 microM) were 0.00286 mg x ml-1 x min-1 and 0.158 mg x ml-1, respectively. One mg of this elastin could be saturated with 5.6 micrograms of HLE. As with elastins isolated from other sources, the hydrolysis of baboon aortic elastin by HLE was highly sensitive to ionic strength, and a biphasic effect was obtained with increasing NaCl concentrations. A nearly 2-fold stimulation of elastolysis was observed at a 0.15M NaCl concentration. Further increase in ionic strength led to a continuous decrease of the rate of elastolysis which paralleled the decrease of adsorption of elastase to baboon aortic elastin. Cathepsin G, but not bovine alpha-chymotrypsin, was able to stimulate the rate of hydrolysis of baboon aortic elastin by HLE. A 1.7 fold stimulation was observed for a 1:1 molar ratio of the two proteinases and rose to 2.1 for a HLE/Cat. G ratio equal to 8.
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PMID:Susceptibility of baboon aorta elastin to proteolysis. 216 85

Elastin was isolated from the human aorta by three different extraction methods. Immunization was carried out in sheep. The presence of antibody against each elastin preparation in the sheep sera was confirmed by immunofluorescence. However, antiserum against elastin isolated by collagenase/guanidine dithioerythritol showed the most specific reactions in the cryostat sections. No cross-reactivity to type I, III and IV collagen, fibronectin, laminin and proteoglycan BM 1 was observed.
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PMID:Preparation of a specific antiserum against elastin of the human aorta. 242 14

Elastin synthesized in response to vascular injury was characterized in terms of its amino acid composition, the biosynthetic labeling of the desmosines and of the heat coacervable polypeptides present in the 2 M urea extract. Neointimal hyperplasia of the chronic variety was induced in rabbit aorta by superficial mechanical lesions. At 4 months following injury the reendothelialized neointimal thickening and the media were excised. Aliquot samples were incubated with [3H] lysine, extracted with 2 M urea, 0.1 M Tris, pH 7.4 and hydrolysed with collagenase. In the residue of the digests the [3H] desmosines were quantified after electrophoretic separation. Elastin was purified from the nonlabeled aliquots of the media and neointimal hyperplasia. It accounted for 60% and 25% of the dry weight of the media and the neointima respectively. Elastin isolated from the media and the neointima had essentially the same amino acid composition. The incorporation of [3H] lysine into desmosines and into coacervable polypeptides indicated that the synthesis of crosslinked elastin is still active in the hyperplasia at 4 months following injury.
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PMID:Biochemical characterization of elastin in neointimal hyperplasia of rabbit aorta. 271 29

The physical and chemical properties of the mammalian aorta are known to vary as a function of distance from the heart. These properties are highly dependent collagen and elastic fibers. In order to evaluate the mechanisms which regulate the accumulation of these two connective tissue proteins, gene expression was evaluated at both the biosynthetic and messenger RNA levels. Short-term (3 h) explant cultures of the medial portion of four segments of the descending aorta in newborn pigs were incubated in the presence of [3H] proline. Collagen production was quantified by collagenase digestion and elastin production was determined by immunoprecipitation. Between the conus arteriosus and the bifurcation of the iliac arteries, relative collagen synthesis increased 2-fold (from 5.8 to 12.0% of total protein synthesis), while relative elastin synthesis declined 10-fold (from 16.4 to 1.6% of total protein synthesis). Similarly, collagen production increased more than 7-fold (from 6.7 to 49.8 X 10(3) molecules/cell/h) while elastin production was reduced more than 3-fold (from 71.8 to 21.0 X 10(3) molecules/cell/h) along this developmental gradient. Elastin synthesis appeared to be controlled to a significant extent by the availability of elastin mRNA, since both cell-free translation and molecular hybridization to a cloned elastin gene probe showed gradients of elastin gene expression. Similarly, collagen synthesis was apparently regulated, at least in part, by an inverse gradient of collagen mRNA, as measured with a cloned cDNA for the pro-alpha 1(I) collagen gene. Marked changes in the amount of non-elastin protein synthesis accompanied differentiation and accounted for larger changes in relative synthesis. These results suggest that the phenotype of the cells of the porcine artery wall is distinct in different regions of this organ at this developmental stage.
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PMID:Longitudinal gradients of collagen and elastin gene expression in the porcine aorta. 383 76

Wharton's jelly of human umbilical cord is known to contain hyaluronic acid and sulphated glycosaminoglycans (probably as proteoglycans) immobilized in an insoluble collagen fibril network. A secondary, independent, insoluble network based on glycoprotein microfibrils of 13 nm diameter and interpenetrated with the collagen network has now been found in amounts corresponding to 9% of the weight of collagen. Elastin, however, is absent. Tissue slices placed in physiological buffer swell to two-fold their in vivo volume. This is due to the influence of the polysaccharides since treatment with either testicular hyaluronidase, Streptomyces hyaluronidase or chondroitinase ABC, causes their quantitative removal and abolishes the swelling tendency of tissue. Tissue so treated remains close to its in vivo volume indicating that for this state the fibrillar network, overall, is in its relaxed unstressed configuration. Subsequent treatment with a protease causes the degradation of the glycoprotein microfibril network and a two-fold increase in tissue volume while treatment with bacterial collagenase, resulting in the solubilization of 46% of the collagen, causes only a slight deswelling. These results suggest that the unstressed configuration of the network system at the in vivo volume of tissue is due to the collagen network being held in compression by the microfibril network. With intact tissue protease digestion with trypsin, in addition, causes a preferential release of sulphated glycosaminoglycans. Hyaluronic acid, however, remains largely immobilized.
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PMID:Evidence for a mechanical coupling of glycoprotein microfibrils with collagen fibrils in Wharton's jelly. 682 35

Aortae from three patients with classic presentation of Marfan syndrome, who died of vascular complications, were subjected to biochemical analyses of the connective tissue; for comparison, aortae from eight age-matched controls, without evidence of connective tissue abnormalities, were examined. Elastin was prepared from the aortae by two techniques. First, the tissues were extracted with 5 M guanidine-HCl, bacterial collagenase digestion and reduction with dithiothreitol (elastin I preparation). Secondly, this material was further purified by extraction with 0.1 M NaOH at 99 degrees C (elastin II preparation). Amino acid analyses of both elastin preparations indicated that the values for desmosine and isodesmosine were reduced in Marfan cases to approximately one-half of the control values. A corresponding increase in lysyl residues was noted in elastin II preparations. Also, the concentration of elastin per milligram dry weight of tissue was reduced in Marfan cases. The hydroxyproline content of elastin was increased in two cases with the Marfan syndrome. Recoveries indicated that the alkali treatment solubilized 46.2% of the elastin I preparations in Marfan aortae compared with 23.7% in controls. In contrast to elastin, the concentration and solubility of collagen were unchanged; the amino acid composition and the genetic types of insoluble collagen isolated by limited pepsin proteolysis were the same in both Marfan and control aortae. The results of our study demonstrate that the cross-linking of aortic elastin is reduced in the three patients with Marfan syndrome. Thus, a defect in elastin could explain the vascular fragility observed clinically in these patients.
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PMID:Marfan syndrome. Demonstration of abnormal elastin in aorta. 717 92

The aim of this study was to investigate the extracellular degrading proteolytic cascade proteins referred to as matrix metalloproteinase-1 (MMP-1), MMP-2, MMP-9, membrane-type matrix metalloproteinase-1 (MT1-MMP), tissue inhibitors of matrix metalloproteinase-1 (TIMP-1), TIMP-2, neutrophil elastase, and alpha1-antitrypsin in human pulmonary emphysema. Localization of MMP-1, MMP-2, MMP-8, MMP-9, MT1-MMP, TIMP-1, and TIMP-2 was verified by immunohistochemical analysis. The results of our study indicated that the immunoreactivity of MMP-1, MMP-8, MMP-9, and TIMP-1 was absent, whereas MT1-MMP and MMP-2 were mainly observed in pneumocytes, fibroblasts, and alveolar macrophages. Although MT1-MMP and MMP-2 were observed both in emphysematous and normal lung tissue, these immunoreactivities were intense in the emphysematous samples. The presence of MMP-1, MMP-2, MMP-9, TIMP-1, and TIMP-2 was confirmed at mRNA level by reverse transcription-PCR analysis and enzyme immunoassay (EIA). However, the only statistical difference that was observed was in MMP-2 and MMP-9 (MMP-2: emphysematous samples, 19.1+/-2.1 versus control samples, 5.2+/-0.60 microg/g protein, p < 0.05; MMP-9: emphysematous samples, 18.4+/-5.6 versus control samples, 8.1+/-2.7 microg/g protein, p < 0.05). Results of the neutrophil elastase as analyzed by EIA, and alpha1-antitrypsin levels as detected by laser nephelometric immunoassay, indicated no statistical difference between the emphysematous and control groups. In addition to the presence of mRNA levels, the level of MT1-MMP according to immunoblot analysis increased in the emphysematous samples. Gelatin zymographic analysis confirmed the presence of both pro and active forms of MMP-2, and the increased ratio of the active form of MMP-2 in emphysematous samples (25.9%+/-2.0% versus 11.2%+/-3.3%, p < 0.05), indicated in situ activation of MMP-2 by MT1-MMP. Elastin zymographic analysis showed elastolytic activity by MMP-2 and MMP-9 but not the reported band of macrophage metalloelastase (MMP-12). The data suggest that the MT1-MMP/MMP-2/TIMP-2 system plays a significant role in the MMP-mediated extracellular matrix degradation and tissue remodeling of emphysematous lungs, and thus may contribute to the weakening of lung parenchyma and lead to the formation of emphysema.
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PMID:Matrix metalloproteinase-mediated extracellular matrix protein degradation in human pulmonary emphysema. 975 52

In this review are presented the last new results of our research group dealing with the molecular structures (atomic level) of tropoelastin, elastin and elastin derived peptides studied by using essentially methods of bioinformatics (theoretical predictions and molecular modelling) linked to experimental circular dichroism spectroscopic studies. We already had characterized both the local secondary structure and some parts of the tertiary structure of the tropoelastin and elastin molecules (human, bovine...), by using either theoretical predictions (local secondary structure, linear epitopes...) and/or experimental data (optical spectroscopic methods: Raman scattering, infrared absorption, circular dichroism). Except the cross-linking regions which are in helical conformations, the whole tropoelastin structure displays a lot of beta-reverse turns which usually belong to irregular structures in proteins. These turns play a key role in other regularly structures orientation (alpha-helix, beta-strand), thus they are very important in the native protein 3D architecture. It is particularly true for human tropoelastin, because its sequence is rich in glycines and prolines, and these residues are frequently met in beta-turns (a beta-turn is made of four consecutive residues which are stabilized by an hydrogen bond). Several types of beta-turns can be defined with the dihedral angles values phi and psi of the two central residues. Thus, by using a very recent updated set of propensities for the amino acid residues to belong to given types of reverse beta-turns (extracted from a reference set of known 3-D structures of globular proteins), we have determined, (by using our home made software COUDES), for all possible tetrapeptides of the human tropoelastin sequence, the distribution and the characterization of the possible type of turns. Thus, it is shown that the locations and/or the types of these reverse beta-turns reveal a regularity and are not all random. This confirms our hypothesis that intra-molecular elasticity of tropoelastin could be explained by the possibility of transitions between conformations involving short beta-strands and beta-turns. This result is of great interest in the construction (by using molecular biology) of elastic biomaterials derived from the elastin sequence (particularly, the elastin derived peptides corresponding to the sequence exon 21--(exon 24--exon 24...). Our study permit also to predict the conformations of specific elastin derived peptides which could have interesting biological activity. Peptides resulting from the degradation of elastin, the insoluble polymer of tropoelastin and responsible for the elasticity of vertebrate tissues, can induce biological effects and notably the regulation of matrix metalloproteinases (MMP-s) activity. Recently, it was proposed that some elastin derived hexapeptides resulting from circular permutations of VGVAPG (a three fold repetition sequence in exon 24 of human tropoelastin) possess MMP-1 production and activation regulation properties. This effect depends on the presence of the tropoelastin specific membraneous receptor 67 KDa EBP (Elastin Binding Protein). Our results obtained by using both circular dichroism spectroscopy and linear predictions confirmed the hypothesis of a structure dependent mechanism with a possibly occurring type VIII beta-turn on the first four residues of the GXXPG sequence consensus which is only present among all active peptides. Thus, we have performed extensive molecular dynamics studies, in both implicit and explicit solvent, on these active and inactive elastin derived hexapeptides. Using our own analysis method of pattern recognition of the types of the beta-reverse-turns followed during the molecular dynamics trajectory, we found that active and inactive peptides effectively form two well distinct conformational groups in which active peptides preferentially adopt conformation close to type VIII GXXP (beta-reverse-turn. The structural role of the C terminal G residue could also be explained. Additional molecular simulations on (VGVAPG)2 and (VGVAPG)3 show the formation of two or three GXXP tetrapeptides adopting a structure close to type VIII beta-reverse-turn, suggesting a local conformational preference for this motif. This observation of a specific structural single and/or repeated motif is in agreement with the circular dichroism spectra of the involved (VGVAPG)1, (VGVAPG)2 and (VGVAPG)3 peptides and then it can be proposed that their biological activities have to be linear. The final aim of this type of work is to understand more about the sequence/structure/function/activity relationships of those structured peptides in order to propose specific sequences (corresponding to specific structures) for best biological activity results.
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PMID:[A turning point in the knowledge of the structure-function-activity relations of elastin]. 1172 5


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