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)

Mycobacterium ulcerans produces an exotoxin in culture which, when inoculated into guinea pig skin, causes inflammation, necrosis, edema, and other histopathological changes resembling those in infections of humans. The toxin was resistant to heat and to alkalies and was moderately acid labile. Toxic activity was destroyed by Pronase, phospholipase, lipase, amylase, and glucosidase but not by trypsin, collagenase, cellulase, lysozyme, hyaluronidase, or neuraminidase. Toxic activity was resistant to treatment with 2-mercaptoethanol, urea, guanidine hydrochloride, p-chloromercuribenzoate, ethylenediaminetetraacetate, and sodium deoxycholate but was destroyed by sodium m-periodate and sodium dodecyl sulfate. The toxin was precipitated by a wide range of ammonium sulfate concentrations. Extraction with chlorofrom-methanol or petroleum ether destroyed its activity. Isopycnic density gradient ultracentrifugation in KBr produced a high-density lipoprotein layer with a 24-fold increase in specific activity. The results indicate that this toxin is a high-molecular-weight phospholipoprotein-polysaccharide complex.
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PMID:Further characterization of Mycobacterium ulcerans toxin. 3 Jun 94

Studies were undertaken to define more fully the antigenic properties of human articular cartilage proteoglycans, in anticipation of its potential contribution to alterations arising in diseased states and following cartilage transplantation. Proteoglycans, extracted from normal, adult articular cartilage by dissociative measures, were subjected to purification by cesium density gradient ultracentrifugation, under conditions facilitating both molecular aggregation and dissociation. A polydisperse population of reactive determinants was observed in immunodiffusion and hemagglutination inhibition systems, employing proteoglycan specific antisera on gradient fractions. Highly aggregated proteoglycan species appeared to contain potentially masked antigenic determinants, which were revealed after guanidine dissociation but not hyaluronidase digestion. Polyacrilamide disc gel electrophoresis in sodium dodecyl sulfate, in conjunction with disc elution experiments, confirmed proteoglycan antigenic polydispersity.
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PMID:Polydispersity of human articular cartilage proteoglycan antigens. 6 14

The proteoglycans of cartilage are complex molecules in which chondroitin sulphate and keratan sulphate chains are covalently linked to a protein core, forming a polydisperse population of proteoglycan monomers. By interaction with hyaluronic acid and link proteins, the monomers form large macromolecular complexes. In vivo the proteoglycans mainly occur in such aggregates. In the electron microsope, the cartilaginous matrix can be seen to be made up of thin collagen fibrils and polygonal granules about 10-50 nm in diameter Addition of the polyvalent cationic dye Ruthenium Red to glutaraldehyde and osmium tetroxide fixatives yields a dense selective staining of the matrix granules. Following a short digestion of cartilage slices with either of the chondroitin sulphate-degrading enzymes hyaluronidase and chondroitinase or with the proteolytic enzyme papain, the matrix granules were few in number or completely absent and the proteoglycan content, measured as hexosamine, decreased by up to 90%. Similarly, extraction of the cartilage with 4 M guanidine-HCl removed all matrix granules and most of the proteoglycans. From these findings, it can be concluded that the matrix granules represent proteoglycans, most probably in aggregate form, and that Ruthenium Red staining may be used to study the distribution of these macromolecules in thin sections. As a complement to chemical studies on proteoglycan structure, it is also possible to observe and measure individual molecules in the electron microscope after spreading them into a monomolecular layer with cytochrome c. This technique has been applied in investigations on proteoglycans isolated from bovine nasal cartilage and other hyaline cartilages. The molecules in the monomer fractions appeared as an extended central core filament to which about 25--30 side-chain filaments were attached at various intervals. The core filament, averaging about 300 nm in length, was interpreted as representing the polysaccharide binding part of the protein core and the side-chain filaments, averaging about 45 nm in length, as representing the clusters of chondroitin sulphate chains. Statistical treatment of the collected data indicated that no distinct subpopulations existed within the monomer fractions. The electron microscopic results correlated well with chemical data for the corresponding fractions and together with recent observations on various aggregate fractions strongly support present concepts of proteoglycan structure.
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PMID:Electron microscopy of cartilage proteoglycans. 6 24

Proteoglycans were extracted from bovine articular cartilage with guanidine-HCl and fractionated in cesium chloride density gradients by equilibrium ultracentrifugation. The acidic glycosaminoglycan (AGAG) components were then determined enzymatically with chondroitinase-ABC and streptomyces hyaluronidase. Under associative and dissociative conditions, the distribution of the AGAG components was as follows: the ratio of 4-sulfated disaccharide units to total AGAG increased with decreasing density gradients whereas that of 6-sulfated disaccharide units to total AGAG increased with increasing density gradients. The ratio of disulfated disaccharide units to total AGAG increased somewhat with decreasing density gradients whereas that of non-sulfated disaccharide units tended to decrease. Although the cartilage proteoglycan macromolecules were heterogeneous, a certain regularity was observed with respect to the distribution of sulfate and the degree of sulfation in the chondroitin sulfate chains of the proteoglycans.
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PMID:Constitutional heterogeneity of the glycosaminoglycans in articular cartilage proteoglycans. 14 4

A very high molecular weight mucin-like glycoprotein was isolated by gel filtration of interphotoreceptor matrix (IPM) from fresh bovine eyes and purified to apparent homogeneity by cesium chloride/guanidine hydrochloride (GuHCl) equilibrium density gradient centrifugation. Although a molecular weight in excess of 10(7) Da is suggested by gel filtration, the presence of SDS or GuHCl did not alter its elution position, indicating that the large size was not simply due to aggregation. Treatment of this material with disulfide reagents, however, led to a decrease in molecular size. On a relative basis, substantially more of this glycoprotein is present in IPM prepared from retina than from retinal pigment epithelium. While the carbohydrate and amino acid composition are not those of a true 'mucin', the large size and many other properties are quite 'mucin-like'. The carbohydrate composition suggests the presence of both N- and O-glycosidically linked sugar chains. The presence of a mucin-type O-glycosidic linkage is indicated by its susceptibility to alkaline cleavage, with concomitant loss of serine and threonine and increase in 240 nm absorbance; production of a fluorescent product upon reaction with cyanoacetamide; lectin binding properties; and production of N-acetylgalactosaminitol upon alkaline borohydride elimination. This glycoprotein was digested by pronase and trypsin, confirming its protein nature, but was resistant to digestion with chondroitin ABC lyase, hyaluronidase and heparinase, as well as RNAase, indicating that these components were not present to any appreciable extent. ELISA for cartilage keratan sulfate was also negative. Centrifugation in CsCl/GuHCl gradients indicated a density much lower than that of a proteoglycan or nucleic acid as well. In vitro biosynthetic studies suggest that both retina and retinal pigment epithelium may be major sources of material in the IPM. The elution patterns of radioactivity were strikingly similar to the UV elution patterns of IPM. The medium from retinal incubations contained very high molecular weight material which was resistant to enzymes which hydrolyse glycosaminoglycans, suggesting that retina may be the source of this high molecular weight, mucin-like glycoprotein.
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PMID:High molecular weight mucin-like glycoproteins of the bovine interphotoreceptor matrix. 154 29

Rabbit corneal proteoglycans were labeled by intrastromal injection of 3H-glucosamine and 35S-sulfate 1 and 2 weeks after partial-thickness radial scalpel incisions. Proteoglycans were extracted with guanidine-HCl and purified by ion exchange chromatography. Wounding caused a marked decrease in the total incorporation of labeled precursors into proteoglycans. The labeled proteoglycans were more readily extracted with guanidine-HCl after wounding. Labeled proteoglycans from wounded corneas had a larger molecular size on gel filtration chromatography than did proteoglycans from control corneas, a result of an increased amount of keratan sulfate in the large molecular size fractions. Analysis of labeled glycosaminoglycan (GAG) from guanidine-extracted proteoglycans and from the corneal tissue after guanidine-HCl extraction showed an increase in the relative amount of heparan sulfate and keratan sulfate after wounding, and a decrease in relative amount of dermatan sulfate. The 35S:3H ratio of heparan and dermatan sulfates increased after wounding, and that of keratan sulfate decreased, suggesting changes in sulfation. Degradation of labeled dermatan sulfate with hyaluronidase and with periodate revealed a 2-fold increase in iduronic acid content and 2-4-fold increase in hyaluronidase-resistant dermatan sulfate in the wounded corneas. Reduction in proteoglycan content, reduced sulfation of keratan sulfate, and accumulation of a high-sulfate, high-iduronic acid dermatan sulfate are previously reported properties of proteoglycan in scar tissue from perforating corneal wounds. Demonstration of these properties in proteoglycan after wounds similar to radial keratotomy incisions suggests that deposition of scar tissue can result from wounds which do not damage Descemet's membrane.
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PMID:Proteoglycans of rabbit corneas with nonperforating wounds. 292 15

The purpose of this study was to examine the nature of the linkage between cell-surface hyaluronate and the plasma membrane. To accomplish this, rat fibrosarcoma cells were cultured in the presence of [3H]-acetate to isotopically label the hyaluronate, and then fixed with glutaraldehyde, which cross-links proteins but does not react directly with hyaluronate. The glutaraldehyde fixation stabilized the cells so that they could be manipulated in ways which would otherwise destroy cells. The fixed cells were then subjected to various treatments, and the amount of hyaluronate remaining on the cell surface was assayed via exhaustive digestion with Streptomyces hyaluronidase. Using this technique, we found that 1) cell-surface hyaluronate was quite stable for extended periods of time even in the presence of a large excess of non-labeled hyaluronate; 2) 4 M guanidine HCl and detergents did not extract a significant portion of cell-surface hyaluronate; 3) solutions of varying ionic strength (0-1 M NaCl) had no effect on the retention of hyaluronate; 4) the cell coat was stable in the range of pH 4-11, but outside this range a significant amount of hyaluronate was released; and 5) treatment with proteases released cell-surface hyaluronate. These results are consistent with the possibility that hyaluronate is covalently linked to a protein associated with the plasma membrane. Further support for this model came from experiments with the detergent Triton X-114, which can be used to separate soluble proteins from hydrophobic proteins. When nonfixed rat fibrosarcoma cells were extracted with this detergent and then partitioned by centrifugation, approximately 30 times as much hyaluronate was present in the detergent fraction which contained the hydrophobic proteins, as compared to the extracts pretreated with trypsin prior to phase separation. Again, these results suggest that cell-surface hyaluronate is directly linked to a hydrophobic core protein intercalated in the plasma membrane.
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PMID:Hyaluronate appears to be covalently linked to the cell surface. 312 2

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

Mesenchymal cell aggregates, termed blastema in vivo, precede cartilage differentiation in vivo and in high-density cell cultures. The galactose specific lectin, peanut agglutinin (PNA), has been shown to be blastema specific (B. Zimmermann and M. Thies, 1984, Histochemistry 81, 353-361). PNA appears to be a marker for precartilage cellular aggregates both in vivo and in vitro. Frozen sections of stage 24 chick wing buds were double stained with PNA-rhodamine and by indirect immunofluorescence with antibody directed against type II collagen. The PNA stained the humeral blastema intensely and extended distal to the level of type II collagen. High-density cultures of stage 24 chick wing buds were also evaluated for the distribution of PNA binding. Sixteen-hour cultures showed the earliest consistent appearance of PNA binding. The PNA-stained areas coincided with hematoxylin-stained cell aggregates. PNA staining was inhibited by 50 mM D(+)-galactose and was not sensitive to 1% testicular hyaluronidase pretreatment. No Alcian blue-staining nodules were present yet at 16 hr. The presence of a precartilage, blastema-specific marker in situ, as well as in precartilage aggregates in cultures, suggests the similarities in chondrogenesis between these two conditions. Stage 19 limb bud cultures did not form nodules but did form aggregates that were PNA positive. Furthermore, single cells that differentiated into chondrocytes on collagen gels or after cytochalasin D treatment lacked PNA-binding material. These results suggest that this material is specific to precartilage aggregates. The PNA-positive material was extracellular in distribution and was removed after brief extraction with 0.5 M guanidine hydrochloride.
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PMID:The detection of a precartilage, blastema-specific marker. 355 59

The hyaluronic acid binding region was prepared by clostripain digestion of chondroitin sulfate proteoglycan isolated from the Swarm rat chondrosarcoma, and biotinylated in the presence of associated hyaluronic acid and link protein. After removal of hyaluronic acid by gel filtration in 4 M guanidine HCl, the biotinylated binding region-link protein complex was used as a specific histochemical probe in conjunction with avidin-peroxidase. Its utility was initially evaluated by comparison with Alcian blue staining of the axial region of 2 to 5 day chick embryos, where staining was seen in the dorsolateral area between the neural tube and the ectoderm, in the perichordal mesenchyme, and in developing limb buds. Light and electron microscopic studies of early postnatal rat cerebellum indicate that hyaluronic acid is primarily localized in the extracellular space of immature brain. Staining specificity was demonstrated by the ability of hyaluronic acid oligosaccharides of appropriate size to block the staining reaction, and by the absence of staining after treatment of tissue sections with protease-free Streptomyces hyaluronidase, which degrades only this glycosaminoglycan.
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PMID:The hyaluronic acid binding region as a specific probe for the localization of hyaluronic acid in tissue sections. Application to chick embryo and rat brain. 404 84


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