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:3.2.1.36 (hyaluronidase)
4,606 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The collagen framework of the intervertebral disc contains two major fibril-forming collagens, types I and II. Smaller amounts of other types of collagen are also present. On examination of the nature and distribution of these minor collagens within bovine disc tissue, type VI collagen was found to be unusually abundant. It accounted for about 20% of the total collagen in calf nucleus pulposus, and about 5% in the annulus fibrosus. It was discovered by serially digesting disc tissue with chondroitin ABC lyase and Streptomyces hyaluronidase that native covalent polymers of type VI collagen could be extracted. Electron micrographs of this material prepared by rotary shadowing revealed the characteristic dimensions of tetramers and double tetramers of type VI molecules, with their central rods and terminal globular domains. Molecular-sieve column chromatography on agarose under non-reducing non-denaturing conditions gave a series of protein peaks with molecular sizes equivalent to the tetramer, double tetramer and higher multimers. On SDS/polyacrylamide-gel electrophoresis after disulphide cleavage, these fractions of type VI collagen all showed a main band at Mr 140,000 and four lesser bands between Mr 180,000 and 240,000. On electrophoresis without disulphide cleavage in agarose/2.4% polyacrylamide only dimeric (six chains) and tetrameric (12 chains) forms of type VI molecules were present. The ability to extract all the type VI collagen of the tissue in 4 M-guanidinium chloride, and absence of aldehyde-mediated cross-linking residues on direct analysis, showed that, in contrast with most matrix collagens, type VI collagen does not function as a covalently cross-linked structural polymer.
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PMID:Type VI collagen of the intervertebral disc. Biochemical and electron-microscopic characterization of the native protein. 312 11

A drug-induced collagen-like syndrome was produced in rats by hydralazine administration for 8, 9 and 10 months. The hyaluronic acid content and the hyaluronidase activity in liver and spleen were studied. A decrease in the hyaluronic acid amount was accompanied by an enhanced activity of hyaluronidase in both tissues. The results provide evidence for metabolic disturbances of glycosaminoglycans in the connective tissue in the collagen disease-like syndrome.
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PMID:Hyaluronic acid content and hyaluronidase activity in liver and spleen of rats with hydralazine-induced collagen-like syndrome. 317 90

A histochemical investigation was carried out on proteoglycans of bovine intervertebral disc. Samples obtained from the "annulus fibrosus" (A.F.) and "nucleus pulposus" (N.P.) were treated with Alcian blue (AB) diluted in solutions of MgCl2 at critical electrolyte concentrations (CEC); some samples were incubated in testicular hyaluronidase before AB treatment. At least four types of elongated AB-proteoglycan particles were recognized: a) in A.F. lamellae and N.P., 1 nm rod-like particles were arranged orthogonally to the collagen fibrils and spaced at a distance equivalent to the fibril D-period (Figs. 1-5); b) within the A.F. lamellae, other 16-20 nm particles formed a close network among the collagen fibrils (Figs. 1,2,3,5); c) in the A.F. interlamellar crevices, 30-50 nm leaf-like particles were present (Fig. 6); d) in the N.P.Z., 20-30 nm leaf-like particles formed a wide-mesh (Fig. 4). The alcianophylic particle sizes suggest they may correspond to proteoglycan monomers in the A.F. lamellae and mostly proteoglycan aggregates in A.F. interlamellar crevices and N.P.. Both alcianophylia degrees at MgCl2 CEC solutions and enzymatic susceptibility indicate the presence of chondroitin sulphate and keratan sulphate and that the large particles in the A.F. interlamellar crevices are the keratan sulphate richest proteoglycans. The features of the observed AB-proteoglycan particles are consistent with previous morphological data reported for other tissues as well as some biochemical data for the intervertebral disc and may be correlated to the composite mechanical properties of this tissue.
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PMID:Localization of different alcian blue-proteoglycan particles in the intervertebral disc. 322 64

This paper examines the role of the extracellular matrix (ECM) in the development of the cornea. After a brief summary of the corneal structure and ECM, we describe evidence suggesting that the differentiation of neural crest (NC) cells into endothelium and fibroblasts is under the control of ocular ECM. We then examine the role of collagen I in stromal morphogenesis by comparing normal corneas with those of homozygous Mov 13 mice which do not make collagen I. We report that, in spite of this absence, the cellular morphology of the Mov13 eye is indistinguishable from that of the wild type. In the 16-day mutant stroma, however, the remaining collagens form small amounts of disorganized, thin fibrils rather than orthogonally organized 20 nm-diameter fibrils; a result implying that collagen I plays only a structural role and that its absence is not compensated for. It also suggests that, because these remaining collagens will not form the normal fibrils that they will in vitro, fibrillogenesis in the corneal stroma differs from that elsewhere. The latter part of the paper describes our current work on chick stromal deposition using corneal epithelia isolated with an intact basal lamina that lay down in vitro approximately 3 microns-thick stromas of organized fibrils similar to that seen in vivo. This experimental system has yielded two unexpected results. First, the amount of collagen and proteoglycans produced by such epithelia is not dependent on whether its substratum is collagenous and we therefore conclude that stromal production by the intact epithelium is more autonomous than hitherto thought. Second, chondroitin sulphate (CS), the predominant proteoglycan, appears to play no role in stromal morphogenesis: epithelia cultured in testicular hyaluronidase, which degrades CS, lay down stromas whose organization and fibril-diameter distribution are indistinguishable from controls. One possible role for CS, however, is as a lubricant which facilitates corneal growth: it could allow fibrils to move over one another without deforming their orthogonal organization. Finally, we have examined the processes of fibrillogenesis in the corneal stroma and conclude that they are different from those elsewhere in the embryo and in vitro, perhaps because there is in the primary stroma an unidentified, highly hydrated ECM macromolecule that embeds the fibrils and that may mediate their morphogenesis.
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PMID:The extracellular matrix of the developing cornea: diversity, deposition and function. 325 Aug 51

Since the pH of the gingival crevice increases from below neutrality in health to above pH 8 in disease, we decided to investigate the effect of environmental pH on the growth and enzyme activity of Bacteroides gingivalis W50. Cells were grown in a chemostat under hemin-excess conditions over a range of pH values; stable growth was observed only between pH 6.7 and 8.3, with the maximum yields obtained between pH 7.0 and 8.0. The enzyme profile of cells varied markedly with pH. Enzymes with a specificity for gingival connective tissue (collagenase, hyaluronidase) were produced optimally at or below neutral pH, whereas trypsinlike activity increased with the growth pH and was maximal at pH 8.0. Chymotrypsinlike activity was generally low, although its activity was highest at the extremes of growth pH, i.e., at pH 6.7 and 8.3. Inhibitor studies provided evidence that the breakdown of collagen involved the concerted action of both a collagenase and the trypsinlike enzyme. The ratio of trypsin to collagenolytic activity rose from 1:1 during growth at neutral pH and below to almost 7:1 during growth at pH 8.3. Thus B. gingivalis appears to be uniquely adapted as a periodontopathic organism in that under environmental conditions likely to prevail during the initial stages of pocket development it produces maximally those enzymes with a tissue-damaging potential. Then, as the pH of the pocket rises during the host inflammatory response, the activity of the trypsinlike enzyme increases markedly, which may enable cells to inactivate key components of the host defenses such as immunoglobulins and complement.
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PMID:Effect of environmental pH on enzyme activity and growth of Bacteroides gingivalis W50. 328

Microfibrils have been identified within and between corneal collagen lamellae in a number of vertebrate species in a variety of developmental and pathological conditions, but they are relatively rare in normal adult animals. The present study was undertaken to analyze corneal microfibrils in adult rabbits using enzymatic digestion techniques. Transmission electron microscopy (TEM) showed clusters of 10-15 nm microfibrils arranged in quasi-parallel bundles within or between orthogonally arranged stromal collagen lamellae. When corneas were fixed with tannic acid/glutaraldehyde, the entire stroma showed increased electron density and microfibrillar bundles were heterogeneously stained. Peripheral fibrils were more electron-dense than those located more centrally. Following sequential detergent solubilization of unfixed corneas, all cellular elements were removed and collagen lamellae were distorted. Microfibrillar bundles remained intact, however, and resembled untreated controls. Subsequent treatment with pepsin, trypsin or elastase resulted in swollen corneal tissues in which collagen lamellae were no longer distinguishable but individual collagen fibrils maintained their morphological integrity. In these tissues microfibrillar bundles were rarely identifiable and were reduced to randomly oriented fragments or clusters of filamentous material. Testicular hyaluronidase or chondroitinase ABC did not affect the fibrils. These data indicate that rabbit corneal microfibrils are proteinaceous and that the tannic acid-staining component of the bundles is not glycosaminoglycan. The fibrils are indistinguishable from those identified as oxytalan in cornea and other ocular tissues. Moreover, their sensitivity to elastase and preferential staining with tannic acid/glutaraldehyde strongly suggest they may be related to the elastic system of fibrils.
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PMID:Ultrastructural analyses of enzyme-treated microfibrils in rabbit corneal stroma. 328 15

A method for the isolation and culture of intact intrahepatic bile ducts from normal rats, and its use in studying putative inducers of biliary epithelial cell (BEC) hyperplasia was developed. Ducts were isolated by sequential perfusion of the liver with EGTA and collagenase-hyaluronidase followed by mild mechanical agitation. The resultant fraction, consisting of numerous small bile ducts within a connective tissue framework, was collected and embedded in a collagen gel and cultured on a raft assembly in Medium 199 supplemented with 15% newborn calf serum and antibiotics. Following 10-15 days in culture, the tissue consisted of dilated bile ducts lined by large cuboidal to elongated BEC. At day 15, the BEC 3H-thymidine-labelling index was 5.56 +/- 0.66% (mean +/- s.e.m.) which is nine times that observed in normal rat BEC in situ and similar to the rate of cell division of BEC lining hyperplastic ductules following bile duct ligation in the rat. Putative cholangiotrophic factors, proline, lithocholic acid and extracts of liver and small intestinal mucosa from normal rats and rats after 3 weeks' total biliary obstruction (TBO), were added to the culture medium for the last 5 days of a 15-day culture. With the exception of the extract of liver following TBO which had a growth inhibitory effect and lithocholic acid which was toxic, these treatments did not result in any alteration in the rate of BEC replication.
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PMID:Isolation and culture of intrahepatic bile ducts and its application in assessing putative inducers of biliary epithelial cell hyperplasia. 330 83

The present study reports on the fine structure of human costal cartilage at different ages in order to obtain information on the morphogenesis of amianthoid fibers. Our results reveal an overall increase of collagen fibril diameter with increasing age, even in areas with no signs of amianthoid transformation. Ultrastructural evidence is presented that this increase in diameter is due to a gathering of the preexisting collagen fibrils. The age-related change in collagen fibril diameter is paralleled by changes in the composition and ultrastructural appearance of cartilage proteoglycans (as revealed by acridine orange staining). Acridine-orange-positive filaments indicative for proteoglycans are markedly reduced in size with advancing age in centrally located regions of costal cartilage. Treatment with testicular hyaluronidase previous to acridine-orange staining leaves these small proteoglycan filaments unaffected. By contrast, the filaments visible after acridine-orange staining in the extracellular matrix near to the perichondrium are susceptible to hyaluronidase treatment. Infrequently, a sharp increase in collagen fibril diameter can be observed in territorial matrix areas of degenerating chondrocytes. This observation is conspicuous at ages of 10 and 20 years. Amianthoid transformation is characterized by the appearance of collagen fibrils strictly arranged in parallel. These amianthoid fibers are embedded in a matrix rich in small acridine-orange-positive filaments similar to the proteoglycan filaments observed in centrally located matrix regions. It can be concluded that extensive remodelling not only of the collagen fibrils but also of the cartilage proteoglycans is involved in the development of amianthoid transformation.
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PMID:Amianthoid (asbestoid) transformation: electron microscopical studies on aging human costal cartilage. 334 45

The present observations demonstrate that quiescent calcium-tolerant adult rabbit cardiac myocytes can be isolated by collagenase-hyaluronidase perfusion and maintained in primary culture for at least 2 wk. Culturing large numbers of myocytes requires that the freshly isolated cells be attached to a suitable substratum such as laminin, type IV collagen, or fetal bovine serum. The cultured myocytes retain their rod-like morphology for approximately 7 days before gradually spreading into a flattened conformation by 14 days. During the 1st wk of culture, contaminating interstitial cells rapidly proliferate, making cultures unsuitable for long-term study. Pure myocyte populations can be established and maintained if freshly isolated cells are cultured in the presence of cytosine arabinoside (Ara-C, 10 microM). This antimetabolite does not appear to adversely affect high-energy phosphates, since ATP and creatine phosphate (CrP) content of the myocytes is maintained at levels normally found in biopsy samples of rabbit myocardium. These results illustrate that an energetically stable population of adult cardiac myocytes can be maintained in primary culture in sufficient numbers to make them useful for future investigations of myocyte function.
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PMID:Attachment and maintenance of adult rabbit cardiac myocytes in primary cell culture. 338 98

We have examined the adhesion of primary Sertoli cells to a seminiferous tubule basement membrane (STBM) preparation in vitro. The STBM isolation procedure (Watanabe, T.K., L.J. Hansen, N.K. Reddy, Y.S. Kanwar, and J.K. Reddy, 1984, Cancer Res., 44:5361-5368) yields segments of STBM that retain their histotypic form in both three-dimensional tubular geometry and ultrastructural appearance. The STBM sleeves contain two laminae: a thick, inner basal lamina that was formed in vivo between Sertoli cells and peritubular myoid cells; and a thinner, outer basal lamina that was formed between myoid cells and sinusoidal endothelial cells. Characterization by immunofluorescence and SDS PAGE revealed that the isolated STBM retained fibronectin, laminin, and putative type IV collagen among its many components. When the STBM sleeves were gently shaken with an enriched fraction of primary Sertoli cells, the Sertoli cells bound preferentially to the lumenal basal lamina at the ends of the STBM sleeves. Few Sertoli cells bound to either the outer basal lamina of the STBM sleeves or to vascular extracellular matrix material which contaminated the STBM preparation. 3T3 cells, in contrast, bound to all surfaces of the STBM sleeves. Pretreatment of the STBM sleeves with proteases, 0.1 M Na metaperiodate, 4 M guanidine HCl, or heating to 80 degrees-90 degrees C inhibited lumenal Sertoli cell binding, but binding was not inhibited by chondroitinase ABC, heparinase, hyaluronidase, or 4 M NaCl. The lumenal Sertoli cell binding occurred in the presence or absence of added soluble laminin, but not fibronectin. The addition of soluble laminin, but not fibronectin, restored random binding of Sertoli cells to trypsinized STBM sleeves. Our in vitro model system indicates that Sertoli cells recognize differences in two basal laminae produced in vivo on either side of myoid cells.
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PMID:Sertoli cell binding to isolated testicular basement membrane. 352 69


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