967 resultados para MATRIX METALLOPROTEINASE


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TSV-DM, a basic metalloproteinase with a molecular weight of 110 kDa, was purified from Trimeresurus stejnegeri venom. TSV-DM degraded the A alpha chain of fibrinogen more rapidly than the B beta chain in a dose dependent manner. The cDNA of TSV-DM encode

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A 50 kDa fibrinogenolytic protease, ohagin, from the venom of Ophiophagus hannah was isolated by a combination of gel filtration, ion-exchange and heparin affinity chromatography. Ohagin specifically degraded the alpha-chain of human fibrinogen and the pr

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A hemorrhagic proteinase, jerdohagin, was purified from Trimeresurus jerdonii venom by gel filtration and ion-exchange chromatographies. It was a single chain polypeptide with an apparent molecular weight of 96 kDa as estimated by SDS-PAGE under the non-reducing and reducing conditions. Internal peptide sequencing indicated that it consisted of metalloproteinase, disintegrin-like and cysteine-rich domains and belonged to the class III snake venom metalloproteinases (class P-III SVMPs). Like other typical metalloproteinases, hemorrhagic activities of jerdohagin were completely inhibited by EDTA, but not by PMSF. Jerdohagin preferentially degraded a-chain of human fibrinogen. Interestingly, jerdohagin did not activate human prothrombin, whereas it cleaved human prothrombin and fragment F1 of activated human prothrombin. (C) 2004 Elsevier Ltd. All rights reserved.

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Poisonous snakebite wound is a popular disease worldwide. However, the pathogenesis remains unclear. In the present study, a novel metalloproteinase atrahagin in Chinese cobra (Naja atra) snake venom was purified, using heparin-sepharose followed by Super

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A new metalloproteinase-disintegrin, named Jerdonitin, was purified from Trimeresurus jerdonii venom with a molecular weight of 36 kDa on SDS-PAGE. It dose-dependently inhibited ADP-induced human platelet aggregation with IC50 of 120 nM. cDNA cloning and sequencing revealed that Jerdonitin belonged to the class II of snake venom metalloproteinases (SVMPs) (P-II class). Different from other P-II class SVMPs, metalloproteinase and disintegrin domains of its natural protein were not separated, confirmed by internal peptide sequencing. Compared to other P-II class SVMPs, Jerdonitin has two additional cysteines (Cys219 and Cys238) located in the spacer domain and disintegrin domain, respectively. They probably form a disulfide bond and therefore the metalloproteinase and disintegrin domains cannot be separated by posttranslationally processing. In summary, comparison of the amino acid sequences of Jerdonitin with those of other P-II class SVMPs by sequence alignment and phylogenetic analysis, in conjunction with natural protein structure data, suggested that it was a new type of P-II class SVMPs. (C) 2003 Elsevier Inc. All rights reserved.

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以前从菜花烙铁头蛇毒中分离纯化到J erdonitin 。与其他Ⅱ型蛇毒金属蛋白酶相比, J erdonitin 由金属蛋白酶和去整合素两个结构域组成。但没有检测到其出血和纤维蛋白原降解活性, 推测可能高压液相色谱的有机溶液影响了其酶活性。采用不含高压液相色谱柱层析的新分离手段分离得到J erdonitin 。J erdonitin 在还原和非还原SDS2PAGE 电泳中分别呈现一条表观分子量为38 和36 kDa 的条带。像其他典型的蛇毒金属蛋白酶一样, J erdonitin 优先降解人纤维蛋白原的alpha 链, 并且该活性能被EDTA 完全抑制, 而PMSF 对其没有影响。J er2 donitin 不诱导小白鼠皮下出血。

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Accumulating evidence suggests that unicellular Archezoa are the most primitive eukaryotes and their nuclei are of significance to the study of evolution of the eukaryotic nucleus. Nuclear matrix is an ubiquitous important structure of eukaryotic nucleus; its evolution is certainly one of the most important parts of the evolution of nucleus. To study the evolution of nuclear matrix, nuclear matrices of Archezoa are investigated. Giardia lamblia cells are extracted sequentially. Both embedment-free section EM and whole mount cell EM of the extracted cells show that, like higher eukaryotes, this species has a residual nuclear matrix in its nucleus and rich intermediate filaments in its cytoplasm, and the two networks connect with each other to form a united network. But its nuclear matrix does not have nucleolar matrix and its lamina is not as typical as that of higher eukaryotes; Western blotting shows that lamina of Giardia and two other Archezoa Entamoeba invadens and Trichomonas vaginali all contain only one polypeptide each which reacts with a mammalia anti-lamin polyclonal serum and is similar to lamin B (67 ku) of mammlia in molecular weight. According to the results and references, it is suggested that nuclear matrix is an early acquisition of the eukaryotic nucleus, and it and the "eukaryotic chromatin" as a whole must have originated very early in the process of evolution of eukaryotic cell, and their origin should be an important prerequisite of the origin of eukaryotic nucleus; in the iamin (gene) family, B-type lamins (gene) should be the ancestral type and that A-type lamins (gene) might derive therefrom.

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Euglena gracilis cell was extracted sequentially with CSK-Triton buffer, RSB-Magik solution and DNase-As solution. DGD embedment-free electron microscopy showed that in the extracted nucleus there was a residual non-chromatin fibrous network. That it could not be removed by hot trichloroacetic acid further supported the idea that it was a non-histone, non-chromatin fibrous protein network, and should be the internal network of the nuclear matrix. After the sequential extraction, the nuclear membrane was removed, leaving behind a layer of lamina; the chromatin was digested and eluted from the dense chromosomes and residual chromosomal structures that should be chromosomal scaffold were revealed. Western blot analysis with antiserum against rat lamins showed that nuclear lamina of the cell possessed two positive polypeptides, a major one and a minor one, which had molecular masses similar to lamin B and lamin A, respectively. Comparing these data with those of the most primitive eukaryote Archezoa and of higher eukaryotes, it was suggested that the lower unicellular eukaryote E. gracillis already had the nuclear matrix structure, and its nuclear matrix (especially the lamina) might represent a stage of evolutionary history of the nuclear matrix. (C) 2000 Editions scientifiques et medicales Elsevier SAS.

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Jerdonitin is a P-II class snake venom metalloproteinase comprising metalloproteinase and disintegrin domains. In this study, we established a high-level expression system in Pichia pastoris and developed a purification strategy for the recombinant Jerdonitin. This recombinant Jerdonitin degraded fibrinogen at a level of activity comparable with its wild type. The effects of recombinant Jerdonitin on inhibiting ADP-induced human platelet aggregation were in a dose-dependent manner with an IC50 of 248 nM. In addition, we reported here that Jerdonitin can significantly inhibit the growth of several cell lines, including human liver cancer cells (Bel7402), human leukemia cells (K562) and human gastric carcinoma cells (BGC823). This study offers recombinant Jerdonitin that will be valuable for further functional and structural studies of Jerdonitin. (C) 2009 Elsevier Ltd. All rights reserved.

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Bone is a complex material with a hierarchical multi-scale organization from the molecule to the organ scale. The genetic bone disease, osteogenesis imperfecta, is primarily caused by mutations in the collagen type I genes, resulting in bone fragility. Because the basis of the disease is molecular with ramifications at the whole bone level, it provides a platform for investigating the relationship between structure, composition, and mechanics throughout the hierarchy. Prior studies have individually shown that OI leads to: 1. increased bone mineralization, 2. decreased elastic modulus, and 3. smaller apatite crystal size. However, these have not been studied together and the mechanism for how mineral structure influences tissue mechanics has not been identified. This lack of understanding inhibits the development of more accurate models and therapies. To address this research gap, we used a mouse model of the disease (oim) to measure these outcomes together in order to propose an underlying mechanism for the changes in properties. Our main finding was that despite increased mineralization, oim bones have lower stiffness that may result from the poorly organized mineral matrix with significantly smaller, highly packed and disoriented apatite crystals. Using a composite framework, we interpret the lower oim bone matrix elasticity observed as the result of a change in the aspect ratio of apatite crystals and a disruption of the crystal connectivity.