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)

Earlier investigations suggested, using electrokinetic evidence, that RNA is present at the surfaces of some types of cultured and freshly isolated cells. In this report, further investigations of the nature of cell surface RNA of cultured Ehrlich ascites (EAT) cells are reported. These experiments were carried out by determining the changes in electrophoretic mobility of EAT cells after treatment with several highly purified nucleases, neuraminidase, and hyaluronidase. The results suggested that cell surface RNA is located at surface sites separate from those susceptible to neuraminidase and hyaluronidase, that alpha and omega termini of RNA are absent from the electrokinetic surface, and that the RNA present at the cell surface might exist predominantly in a double-stranded form. A model is proposed in which cell surface RNA strand termini are buried out of the electrokinetic surface, but where RNA extends from these buried termini into the electrokinetic surface in loops.
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PMID:Electrokinetic determinations of enzymatic susceptibilities of cell surface-associated RNA. 616 60

Although glycosaminoglycans (GAGs) have been postulated to play a role in the regulation of intraocular pressure, structural localization of specific varieties of GAGs in the outflow system is necessary before their precise role can be determined. In this study, the outflow system of the cat was stained with ruthenium red to identify GAGs with the electron microscope. The composition of the ruthenium red-stainable material was determined by predigestion of tissues with testicular hyaluronidase, neuraminidase, or papain. Testicular hyaluronidase-sensitive GAGs were located on the surfaces of the endothelial cells in the trabecular meshwork and aqueous plexus, within their basal laminae, and in the amorphous tissue of the trabecular beams and tissue adjacent to the aqueous plexus. Collagen and elastic fibers throughout the outflow system were also associated with ruthenium red-stainable material that was resistant to testicular hyaluronidase. Connective tissue GAGs, but not endothelial cell-associated GAGs, were demonstrated to be complexed to protein, since they were disrupted by papain treatment. Neuraminidase-sensitive material (sialoglycoprotein) was identified only on the lumenal surface of the endothelial cells of the aqueous plexus. The complex distribution of GAGs and order polyanions in the outflow system of the cat suggests that the these macromolecules may serve more than one function.
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PMID:Distribution of glycosaminoglycans in the aqueous outflow system of the cat. 617 75

The location and chemical composition of anionic sites in Bruch's membrane (BM) were examined using cationic probe molecules demonstrable in electron microscopic preparations and tissue digestion with specific degradative enzymes. Ruthenium red and native lysozyme revealed densities distributed at regular intervals in two major components of BM: the basal laminae of the retinal pigment epithelium (RPE) and choriocapillary endothelium (EN). Staining was not observed with succinylated lysozyme (anionic). Colloidal iron also failed to stain BM components. Following crude heparinase treatment at 43 degrees C (specific for heparan sulfate) anionic sites in the RPE basal lamina were not demonstrable with either ruthenium red or native lysozyme. Sites in the EN basal lamina were not affected. Chondroitinase treatment removed almost all of the ruthenium red-positive material in the EN basal lamina; lysozyme binding here was markedly reduced. No changes were observed in the RPE basal lamina after chondroitinase digestion. There was no morphological evidence for site removal by either neuraminidase or leech hyaluronidase, although a detachment of the RPE from BM often occurred after incubation of eye tissue in the latter. Pronase E removed all stainable material. These findings indicate that anionic sites in BM consist to a large extent of chondroitin sulfates and heparan sulfate.
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PMID:Location and chemical composition of anionic sites in Bruch's membrane of the rat. 617 64

Differential localization of glycoconjugates was detected on microvilli and microridges of the intact cell surface of frog pronephric tumor cells in tissue culture. Alcian blue and Alcian blue/PAS staining showed a heavy concentration of dye limited to the unique short microvilli and extensive microridges of the tumor cells as previously seen with SEM (Tweedell and Williams 1976). Staining was absent or greatly reduced on microvilli of the normal pronephric cell surface. Previous exposure of each kind of cells to neuraminidase or extraction by mild hydrolysis removed the active staining sites but Alcian blue uptake was unaffected by prior digestion with testicular hyaluronidase. Fluorescein isothiocyanate (FITC) bound wheat germ agglutinin (WGA) produced a similar pattern of fluorescence on the microvilli of the tumor cells and a limited distribution on the normal cells. Digestion with neuraminidase preferentially removed but did not completely eliminate the surface binding of WGA on both the normal and tumor cells. Exposure of tumor cell monolayers to FITC bound limulin, a lectin specific for sialic acid, also produced an intense surface fluorescence on the microvilli and ridges of tumor cells. Prior treatment with neuraminidase prevented the surface fluorescence but not internal binding. Normal pronephric cells gave sparse surface fluorescence but extensive internal binding. Each procedure indicates a preferential localization of complex carbohydrates, including sialic acid, on the unique microvilli of the tumor cells. Concurrent assays for sialic acid recovered from the tumor cells indicated that lectin bound surface sialic acid was removable with neuraminidase.
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PMID:Localization of glycoconjugates on the surfaces of pronephric tumor cells in vitro. 618 38

Glycoproteins and proteoglycans synthesized by human keratinocytes in medium containing D-[1-14C]glucosamine were extracted and analysed by polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate. Extraction of the labelled keratinocytes with 0.5% Triton X-100 removed most of the glycoconjugates and left the cytoskeleton and nuclear residue adherent to the substratum. In addition to the cytoskeletal proteins, there was a relatively simple profile of glycoproteins and glycosaminoglycans associated with this adherent cytoskeleton. These consisted of eight glycoproteins in the mol.wt. range 99000-232000, five proteins in the keratin region (mol.wt. 42000-61000), hyaluronic acid and a sulphated glycosaminoglycan. Surface labelling of the keratinocytes with galactose oxidase (with or without neuraminidase)/KB3H4 revealed that many of the glycoproteins were exposed on the cell surface. The importance of the glycoproteins and proteoglycans in attaching the keratinocytes to the substratum was examined by studying their expression after incubation in medium containing tunicamycin and their degradation after digestion with trypsin and hyaluronidase. These studies, together with an examination of the glycoconjugates released by sequential extraction with 0.5% Triton X-100 followed by 0.2% sodium dodecyl sulphate, revealed that the glycoprotein of mol.wt. 232000 has an important role in mediating the attachment of keratinocytes to the substratum.
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PMID:Glycoproteins and glycosaminoglycans synthesized by human keratinocytes in culture. Their role in cell-substratum adhesion. 619 5

The nature of Cuprolinic Blue-positive anionic filaments in mouse lung alveoli has been characterized. The contrast of filaments in the alveolar basement membrane of type I epithelial cells was lost on treatment with nitrous acid and pronase (without prefixation). In contrast, neither neuraminidase, chondroitinase ABC or AC, nor Streptomyces hyaluronidase had any effect. Treatment with pronase (after prefixation) and 2.0 M MgCl2 (after prefixation) also had no effect, indicating that the filaments are heparan sulphate proteoglycans. The filaments in the alveolar basement membrane of type II epithelial cells and in the capillary basement membrane of the endothelial cells were also nitrous acid sensitive, but chondroitinase ABC-insensitive. A model in which the whole alveolus contains a single layer of heparan sulphate-containing proteoglycan monomers is proposed. Furthermore, the collagen fibril associated filaments remained unaffected after treatment with nitrous acid, neuraminidase or Streptomyces hyaluronidase, or after digestion with pronase (after prefixation) and treatment with 2.0 M MgCl2 (after prefixation). These filaments, however, could no longer be detected when digestion with chondroitinase ABC or pronase (without prefixation) was applied; chondroitinase AC treatment clearly affected the filaments, although they still were visible. These results indicate that the filaments are dermatan sulphate-containing proteoglycans. Some functional aspects of the proteoglycans are discussed.
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PMID:Staining of proteoglycans in mouse lung alveoli. II. Characterization of the Cuprolinic blue-positive, anionic sites. 620 77

Longitudinal slices of 12 freshly extracted human third molars fixed in 10 per cent neutral formalin were demineralized with 1M lactic acid. Ultrathin sections of slices were stained with ruthenium red or silver methenamine. The reaction products were mainly found in the prism sheath regions. To identify the mucosubstances, the digestion tests with chondroitinase ABC, AC, hyaluronidase and neuraminidase were performed. It was concluded that the major component of the organic matrix of inner human dental enamel is chondroitin 4-sulphate or chondroitin 6-sulphate localized in prism sheath regions and inter-crystalline spaces.
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PMID:Nature and distribution of mucosubstances in human mature enamel identified by enzyme electron microscopy. 621 44

Jelly coat of sea-urchin eggs consists of polysaccharides and glycoproteins. Some properties of jelly coat have already been investigated, but not histochemically. The oogenesis in Paracentrotus lividus was studied histologically and the oocytes were classified into six different stages. The extracellular jelly appeared first around the growing oocytes II which remained attached to the germinal epithelium. The jelly became thicker when the oocyte approached maturation. Histochemical analysis revealed that the jelly consists of mucopolysaccharide-protein-complexes. The polysaccharide component is composed of both neutral and acid mucopolysaccharides. The former are amylase-resistant. The acid mucopolysaccharides contain both carboxyl and sulfate groups, which are in close proximity to vicinal hydroxyl groups. Sulfated mucopolysaccharide is hyaluronidase-resistant. Sialic acid could not be clearly demonstrated, because it seems to be resistant to neuraminidase. Pepsin digestion indicated the masking of acidic groups by proteins which compete with basic dyes (Alcian blue, Azure A, coriphosphine etc.). Proteolytic digestion enhanced dye-binding ability of jelly, but removed also some of the periodate-reactive mucosubstances. Also a protein component could be demonstrated histochemically. No histochemical difference between jelly coat of oocytes and that of eggs has been found. The possible molecular structure of jelly coat is discussed.
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PMID:Histochemical studies of jelly coat of sea-urchin eggs during oogenesis. 621 73

Sulfated acidic mucopolysaccharides have been found to be significant components of "protein plugs" in patients with chronic pancreatitis. The precise identification of the mucopolysaccharides and their distribution within the protein plugs may clarify the pathogenesis of the plugs. Pure pancreatic juice from five patients with chronic pancreatitis was obtained by endoscopic retrograde catheterization of the papilla of Vater. Enzymes for digestion of the plugs included hyaluronidase of the bovine testes and streptomyces hyalurolyticus, chondroitinase ABC and AC, and sialidase (neuraminidase). Our study indicated that: I) Sialic acid is distributed throughout the plugs and may be a major component, followed by a lesser amount of chondroitin sulfate B. 2) Chondroitin sulfate A, C, D and E and chondroitin may be minor components. 3) Hyaluronic acid is negligible in the plugs.
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PMID:Histochemical studies on enzyme-digested protein plugs of patients with chronic pancreatitis: a preliminary report. 622 98

Ruthenium red was used to stain microfibrils in rat aorta after incubation of the tissues with or without one of the enzymes trypsin, collagenase, phospholipase C, chondroitinase ABC, hyaluronidase or neuraminidase, or the reducing agent dithiothreitol. Microfibrils exhibiting periodicity of ruthenium red binding were associated with elastic laminae and collagen fibrils and appeared to attach these structures to each other as well as to basal lamina. Microfibrils in rat and human aorta demonstrated fibronectinlike immunoreactivity, therefore fibronectin may be a component of aorta microfibrils and important in the architecture of blood vessels.
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PMID:Microfibrils in the aorta. 622 39


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