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  • 11
    Digitale Medien
    Digitale Medien
    Springer
    Calcified tissue international 14 (1974), S. 291-299 
    ISSN: 1432-0827
    Schlagwort(e): Bone ; Collagenase ; Lysozyme
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Beschreibung / Inhaltsverzeichnis: Résumé Du lysozyme de blanc d'œuf, ainsi que des protéines basiques, telles que de l'histone et une base dépourvue de protamine, semblent inhiber la collagénase osseuse de souris. L'inhibition de collagénase osseuse de souris par le lysozyme est mise en évidence lorsque l'activité de la collagénase est étudiée en utilisant du collagène comme substrat à l'état solide, mais non lorsque le collagène est utilisé en solution. D'autre part, l'inhibition de l'activité en collagénase par l'histone et une base dépourvue de protamine est observée dans les deux systèmes. L'inhibition de collagénase ossuese de souris par des molécules polyanioniques est intéressante, étant donné que des travaux antérieurs ont montré que plusieurs molécules polyanioniques telles que l'héparine, le sulfate de dextrane et l'acide polyethylenesulfonique augmentent l'activité de collagénase osseuse de souris dans les mêmes conditions expérimentales. Comme le lysozyme est largement présent dans les tissus conjonctifs et que sa concentration carie avec l'ampleur du remaniement tissulaire, l'inhibition de la collagénase osseuse de souris suggère un role éventuel dans la régulation de la dégradation du collagène, pendant le remaniement des tissus collagéniquesin vivo au cours d'états normaux et pathologiques.
    Kurzfassung: Zusammenfassung Lysozyme aus Hühnereiweiß sowie Basis-Proteine, wie z. B. Histon und Protamin-freie Basen, erwiesen sich als Hemmer der Mäuseknochen-Kollagenase. Diese Hemmung durch Lysozym wurde festgestellt, wenn für die Messung der Kollagenase-Aktivität Kollagen in Substanz als Substrat verwendet wurde, nicht aber, wenn das Substrat aus gelöstem Kollagen bestand. Andererseits wurde die Hemmung der Kollagenase-Aktivität durch Histon und Protamin-freie Basen in beiden Versuchssystemen festgestellt. Die Hemmung von Mäuseknochen-Kollagenase durch polykationische Moleküle ist interessant, vor allem im Hinblick auf frühere Feststellungen, daß mehrere polyanionische Moleküle, wie Heparin, Dextransulfat und Polyaethylensulfonsäure, die Aktivität der Mäuseknochen-Kollagenase unter denselben experimentellen Bedingungen erhöhen. Da Lysozym in Bindegeweben überall verteilt ist und da dessen Konzentration mit der Neubildungsrate des Gewebes variiert, läßt die Hemmung der Mäuseknochen-Kollagenase durch Lysozym dessen mögliche Rolle in der Regulierung des Kollagenabbaues vermuten, und zwar während der Neubildung von Kollagengeweben in vivo in normalen und pathologischen Zuständen.
    Notizen: Abstract Egg white lysozyme, as well as basic proteins such as histone and protamine-free base, were found to inhibit mouse bone collagenase. The inhibition of mouse bone collagenase by lysozyme was detected when the activity of the collagenase was assayed using collagen as the substrate in the solid state, but not when the collagenase activity was assayed using collagen in solution as the substrate. On the other hand, the inhibition of collagenase activity by histone and protamine-free base was observed in both assay systems. The inhibition of mouse bone collagenase by polycationic molecules is interesting in light of previous findings that several polyanionic molecules, such as heparin, dextran sulfate and polyethylenesulphonic acid, enhance the activity of mouse bone collagenase under the same experimental conditions. Since lysozyme is widely distributed in connective tissues and its concentration varies with the rate of tissue remodeling, the inhibition of mouse bone collagenase by lysozyme suggests its possible role in the regulation of collagen degradation during the remodeling of collagenous tissuesin vivo during normal and pathological states.
    Materialart: Digitale Medien
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  • 12
    Digitale Medien
    Digitale Medien
    Springer
    Calcified tissue international 12 (1973), S. 247-258 
    ISSN: 1432-0827
    Schlagwort(e): Bone ; Collagenase ; Heparin ; Collagen
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Beschreibung / Inhaltsverzeichnis: Résumé La quantité de collagénase d'os de souris, obtenue dans un milieu de culture d'os, cultivéin vitro, est augmentée pas l'addition d'héparine à une concentration optimale d'environ 50 unités/ml de milieu de culture. Le sulfate de dextrane et le Treburon (un ester polysaccharide-sulfurique synthétique), qui sont voisins au point de vue chimique et structural à l'héparine, sont aussi efficaces que l'héparine pour augmenter la quantité de collagénase de l'os de souris, récupérée dans le milieu de culture. L'héparine, outre son action de stimulation de synthèse et/ou de libération de callogénase d'os de souris, augmente aussi l'activeté spicifique des préparations globales et purifiées de l'enzyme, dont l'activité est testée sur du collagène à l'état solide comme substrat. Aucune augmentation d'activité enzymatique n'est notée lorsque du collagène en solution est utilisé comme substrat. Le sulfate de dextrane est aussi effectif que l'héparine pour obtenir une augmentation de l'activité enzymatique, en utilisant le collagène solide comme substrat. Ni l'héparine ou le sulfate de dextrane augmente l'activité de la collagénase deClostridium histolyticum. Pour la première fois, une collagénase tissulaire purifiée dégrade et solubilise du collagène tissulaire non dénaturé et insoluble à 37° C. De plus, étant donné que cette action est nettement augmentée par l'addition d'héparine, il semble que cette dernière et des substances similaires peuvent jouer un rôle important dans la régulation de la dégradation collagénique pendant le remaniement des tissus collagéniquesin vivo.
    Kurzfassung: Zusammenfassung Die Menge von Mäuseknochen-Kollagenase, die sich im Gewebezucht-Medium vonin vitro gezüchteten Knochen wiederfindet, konnte durch Zusatz von Heparinat in einer optimalen Konzentration von ungefähr 50 E/ml Medium erhöht werden. Dextransulfat und Treburon (ein synthetischer Polysaccharid-Sulfatester), welche strukturmäßig und chemisch dem Heparin nahestehen, wirkten sich auf die Erhöhung der im Gewebezucht-Medium zurückgewonnenen Mäuseknochen-Kollagenase im gleichen Maße aus wie Heparin. Nebst der stimulierenden Wirkung auf die Synthese und/oder die Freisetzung von Mäuseknochen-Kollagenase vermochte Heparin auch die spezifische Aktivität von ungereinigten und von gereinigten Enzympräparaten zu erhöhen, wenn für den Versuch Kollagen in fester Form als Substrat verwendet wurde. Mit gelöstem Kollagen als Substrat trat diese Wirkung dagegen nicht ein. Dextransulfat zeigte die gleiche Wirksamkeit wie Heparin, indem es die Enzymaktivität zu erhöhen vermochte, wenn Kollagen in fester Form als Substrat vorlag. Weder Heparin noch Dextransulfat erhöhten die Aktivität der Kollagenase ausClostridium histolyticum. Erstmals konnte gezeigt werden, daß eine gereinigte Gewebe-Kollagenase in der Lage ist, nicht-denaturiertes, unlösliches Gewebekollagen bei 37° sowohl abzubauen als auch aufzulösen. Da diese Wirkung durch Zusatz von Heparin noch deutlich erhöht werden konnte, läßt sich überdies vermuten, daß Heparin und heparinähnlichen Substanzen bei der Regulierung des Kollagen-Abbaues während der Umgestaltung von Kollagengewebein vivo eine wichtige Rolle zufällt.
    Notizen: Abstract The amount of mouse bone collagenase recovered in the tissue culture medium of bone culturedin vitro was increased by the addition of heparin at an optimal concentration of approximately 50 units/ml of tissue culture medium. Dextran sulfate and Treburon (a synthetic polysaccharide-sulfuric ester) which are structurally and chemically related to heparin were as effective as heparin in increasing the amount of mouse bone collagenase recovered in the tissue culture medium. In addition to stimulating the synthesis and/or release of mouse bone collagenase, heparin was also found to increase the specific activity of both crude and purified preparations of the enzyme when assayed using collagen in the solid state as the substrate, but showed no enhancement of enzyme activity when assayed using collagen in solution as the substrate. Dextran sulfate was as effective as heparin in increasing the activity of the enzyme using collagen in the solid state as a substrate. Neither heparin or dextran sulfate enhanced the activity ofClostridium histolyticum collagenase. For the first time, a purified tissue collagenase has been shown to both degrade and solubilize undenatured, insoluble tissue collagen at 37°. Moreover, since this action was markedly enhanced by the addition of heparin, it suggests that heparin and similar substances may play an important role in the regulation of collagen degradation during the remodeling of collagenous tissuesin vivo.
    Materialart: Digitale Medien
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  • 13
    ISSN: 1432-0827
    Schlagwort(e): Calcification ; Calciphylaxis ; Skin ; Serine Phosphate ; Threonine Phosphate ; γ-Carboxyglutamic Acid
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary The amount of non-collagenous proteins is increased greatly during the pathological calcification of rat skin experimentally induced by dihydrotachysterol (DHT) and Ovalbumin (topical cutaneous calciphylaxis). This is accompanied by an increase in the total amount and concentrations of protein-bound serine phosphate [Ser(P)], threonine phosphate [Thr(P)] and γ-carboxyglutamic acid (Gla), almost all of which can be extracted from the tissue and can be dissociated from collagen in 0.5M EDTA. The EDTA-soluble, non-collagenous proteins are rich in aspartic and glutamic acids, similar to the non-collagenous, EDTA-soluble proteins of bone, cementum and calcified cartilage, and quite distinct from those of dentin and enamel.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 14
    ISSN: 1432-0827
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary Uncalcified samples of turkey tendon obtained prior to calcification, and other samples from areas of tendon that never calcify, contain little or no 0-phosphoserine [Ser(P)], 0-phosphothreonine [Thr(P)] and γ-carboxyglutamic acid (Gla). Significant amounts of all three of these Ca2+-binding amino acids, which are found in EDTA-extractable, non-collagenous proteins, are detected coincident with the onset of mineralization of a tendon and increase in concentration as mineralization proceeds.
    Materialart: Digitale Medien
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  • 15
    Digitale Medien
    Digitale Medien
    Springer
    Calcified tissue international 36 (1984), S. 291-301 
    ISSN: 1432-0827
    Schlagwort(e): Bone ; Mineral ; Amorphous calcium phosphate ; X-ray diffraction ; Radial distribution function
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary X-ray diffraction radial distribution function analysis was used to determine if a significant amount of an amorphous solid phase of calcium phosphate exists in bone, and if so, whether the amount varies as a function of age and maturation. Unfractionated cortical bone from embryonic and posthatch chicks of various ages and a low-density fraction of embryonic bone were studied. No evidence was found for the presence of an amorphous solid phase of calcium phosphate in any of the samples studied, including the recently deposited bone mineral of the low density fraction of embryonic bone. As little as 12.5% of synthetic amorphous calcium phosphate (ACP) added to bone was readily detected by the radial distribution function technique used. The results clearly indicate that the concept that ACP is the initial solid mineral phase deposited in bone, and the major mineral constituent of young bone is no longer tenable. The concept does not provide an accurate description of the nature of the initial bone mineral deposited, or the changes that occur with maturation, nor can it acount for the compositional and X-ray diffraction changes that the mineral component undergoes during maturation and aging.
    Materialart: Digitale Medien
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  • 16
    ISSN: 1432-0827
    Schlagwort(e): 31P NMR spectroscopy ; Phosphoprotein ; Dentin ; Calcium ; Inorganic orthophosphate ; Bovine
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary The single phosphoprotein of fetal calf dentin, having a molecular weight of approximately 94,000 and a phosphorus content of 8% (w/w), was examined by31P NMR spectroscopy. The single resonance at 3.7 ppm at pH 10 and its chemical shift during acid titration established the phosphomonoester nature of the organic phosphorus moiety. During titration of the phosphoprotein with CaCl2 in the presence of inorganic orthophosphate ions, line broadening for the orthophosphate resonance was both phosphoprotein- and calcium-dependent, indicating ternary complex formation. The data indicate that the phosphoprotein of fetal calf dentin binds both calcium and inorganic orthophosphate ions and therefore has the requisite physical chemical properties necessary for it to facilitate the heterogeneous nucleation of a Ca-PO4 solid phase from solution during tissue mineralization.
    Materialart: Digitale Medien
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  • 17
    Digitale Medien
    Digitale Medien
    Springer
    Journal of materials science 19 (1984), S. 723-736 
    ISSN: 1573-4803
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Maschinenbau
    Notizen: Abstract An investigation of the molecular structure of bone mineral and synthetic calcium phosphates was carried out using radial distribution function (RDF) techniques. The X-ray data were collected using CuKα and MoKα radiation to insure the validity of the RDFs. Synthetic preparations of hydroxyapatite (HA) varying in their crystal size and crystallinity, and amorphous calcium phosphate (ACP), were studied, as well as bone samples from a 1-year-old chicken and 16-day embryonic chicks. Mixtures of embryonic bone and synthetic ACP were also investigated. The RDFs of bone and crystalline HA samples are similar in peak position, and show evidence of an atomic order extending to 2.5 nm and beyond. The RDF of ACP differs from that of HA, showing only short range order up to 0.9 nm, as well as small differences in peak shape. The decrease in intensity of the RDF function with increasing distance (r), observed with both HA and bone samples can be related to a decrease in crystallinity and crystal size. The RDF data indicate there is no significant amount of ACP in either very young or mature bone. The RDFs of the embryonic bone + synthetic ACP mixtures showed that a small amount of ACP can be readily detected in a sample of bone with a poorly crystalline mineral phase; from this we estimate the threshold for detection of ACP in bone to be 12% or less.
    Materialart: Digitale Medien
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  • 18
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 19
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 224 (1989), S. 139-153 
    ISSN: 0003-276X
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Medizin
    Notizen: Samples of decalcified chicken bone together with varying concentrations of phosphoproteins from bone or egg yolk (phosvitin) were used in vitro as heterogenous nucleators for the induction of Ca-P apatite crystals. The lag time between exposure of the collagen-phosphoprotein complexes and the time nucleation of crystals occurred decreased as the concentration of Ser(P) and Thr(P) increased. Enzymatic cleavage of the phosphate groups by wheat germ and phosphatase reversed this effort, indicating that the phosphate group per se principally facilitated the nucleation of Ca-P crystals by the phosphoprotein complex and collagen.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 20
    ISSN: 1058-8388
    Schlagwort(e): Embryonic development ; hXBP-1 ; Basic domain/leucine zipper protein ; Pancreas ; Salivary glands ; TIMP ; Alkaline phosphatase ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Medizin
    Notizen: The spatial and temporal distribution of transcripts for the TRE/CRE-binding basic region-leucine zipper protein hXBP-1 was determined by in situ hybridization. Analysis of embryos from day 10.5 to 18.5 pc revealed high level expression of hXBP-1 RNA in two developing organ systems: (1) in bone and cartilage cells of the developing skeleton and toothbuds, and (2) in exocrine glands including the pancreas and the submandibular and salivary glands. High level expression was also found in whisker follicles and in selected cells in brown adipose tissue. In the developing skeleton, hXBP-1 RNA was expressed starting on day 11.5 pc in osteoblasts of newly formed intramembranous bone. Thereafter, hXBP-1 was expressed in both osteoblasts and preosteoblasts in bone formed directly by intramembranous formation as well as in bone formed during endochondral ossification. The most intese signal was observed in preosteoblasts and osteoblasts of newly forming bone. At day 11.5 pc low level hXBP-1 expression was also observed in matrix secreting chondroblasts of bones which are formed initially of cartilage, at the stage where they consist entirely of cartilage, at the stage where they consist entirely of cartilage. Signal was also present in matrix producing chondroblasts of the mature zone of the growth region during endochondral ossification although at significantly lower level than in osteoblasts. hXBP-1 is thus the first transcription factor described, to our knowledge, whose level of expression is modulated during the osteoblast developmental sequence in vivo. The pattern of expression of hXBP-1 in the developing skeleton was found to be very similar to that of the genes encoding the tissue inhibitor of metalloproteinase and alkaline phosphatase throughout development. These observations suggest that hXBP-1 may play a role in regulating the expression of tissue specific genes (TIMP, osteonectin, osteopontin, osteocalcin) expressed in osteoblasts. It is intriguing that the promoter regions of several such genes contain potential hXBP-1 binding sites. © 1993 Wiley-Liss, Inc.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
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