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)

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

We previously demonstrated that epithelial cells growing in primary cultures derived from normal and neoplastic mouse mammary tissues are indistinguishable on the basis of morphology, surface topography, agglutinability by concanavalin A, or of number, cytoplasmic location, or organization of microtubules and actin-containing microfilaments. In the present study, the modulation and interrelationships of these features were investigated using the drugs colchicine and cytochalasin B and the enzymes trypsin, collagenase, and hyaluronidase. Untreated cells of both types were only weakly agglutinable by concanavalin A. Pretreatment of the cells with colchicine, cytochalasin B, or hyaluronidase increased cytoagglutination by the lectin dramatically, whereas neither trypsin nor collagenase significantly altered reactivity of the cells. Binding studies utilizing fluorescein-tagged concanavalin A indicated that the enhanced agglutinability did not correlate with any particular distribution of lectin receptors on the cells. At the doses used, colchicine and cytocholasin B induced disruption of microtubules and microfilament networks, respectively, but no effects on either type of cytoskeletal element were observed after hyaluronidase, trypsin, or collagenase. The increased agglutinability was not associated with any specific surface conformation since scanning electron microscopy revealed that untreated cells and cells exposed to colchicine, hyaluronidase, and collagenase were flat and possessed variable numbers of small microvilli. In contrast, following incubation with cytochalasin B or trypsin, the cells underwent retraction and rounding, and developed complex surface structures such as blebs, ruffles, and filopodia. Thus, no single factor appeared responsible for determining the agglutinable or nonagglutinable state of the mammary cells. Morover, no differences were detected in the surface responses of the normal and malignant cells under any of the conditions used.
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PMID:Comparative responses of normal and malignant mouse mammary cells to modulation of surface properties. 624 4

Purpura was grossly observable in albino mice 6 to 8 h after the intraperitoneal injection of sterile, deoxyribonuclease-treated, cell-free extracts prepared by sodium deoxycholate-induced lysis, sonic disruption, Parr bomb treatment, autolysis without sodium deoxycholate, or alternate freezing and thawing of washed suspensions of Streptococcus pneumoniae type I. Cell-free extracts obtained from sonically disrupted, heat-killed cells (100 degrees C for 20 min) did not contain purpurogenic activity. The reaction was maximal at approximately 24 h postinjection, started to fade slowly after 24 to 48 h, and usually was not grossly observable by 4 to 6 days postinjection. The purpura-producing principle (PPP) in the cell-free extract was purified by sequential ammonium sulfate precipitation, protamine sulfate precipitation, Sepharose 6B gel filtration, wheat germ lectin-Sepharose 6MB affinity chromatography, ribonuclease and trypsin treatment, and a second Sepharose 6B gel filtration step. The final preparation (i) contained glucosamine (5.6%), muramic acid (8.0%), neutral carbohydrate (12.8%), phosphate (8.0%), orcinol-reactive material (6.0%), and Lowry-reactive material (1.6%), and (ii) was free of detectable amounts of deoxyribonucleic acid, capsular polysaccharide, neuraminidase, cytolysin, and hyaluronidase. The isoelectric point and molecular size of the PPP were approximately pI 3.0 and several million daltons, respectively, and the activity remained in the supernatant fluid after centrifugation for 1 day at 105,000 x g. PPP activity was destroyed by incubation with egg white lysozyme and sodium metaperiodate but was resistant to trypsin, pronase, alpha-amylase, deoxyribonuclease, ribonuclease, alkaline phosphatase, pancreatic lipase, 7% trichloroacetic acid, 6 M urea, autoclaving (121 degrees C) for 30 min, and mild acid and alkali exposure. Our observations indicate that the PPP requires intact beta-1,4-glucosidic linkages for activity and support the working hypothesis that activity is associated with pneumococcal peptidoglycan solubilized by the bacterium's autolysin.
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PMID:Characterization of pneumococcal purpura-producing principle. 624 53

Chick embryo fibroblasts constitute a useful model for investigating cell surface differentiation using Ricinus lectin as a marker. Fibroblasts from 8-day chick embryos had two classes of Ricinus lectin binding sites, whereas those from 16-day embryos displayed only one class. Hyaluronidase treatment of fibroblasts from 8-day embryos had no effect on their capacity to bind Ricinus lectin; however after this treatment, 16-day cells resembled 8-day cells since the former also exhibited two classes of lectin-binding sites. Treatment with hyaluronidase released 2-5 times more hyaluronic acid from the older cells than from the younger cells. The same hyaluronidase treatment did not change the number of 8-day cells detached by trypsin from the substrate, but increased the number of detached 16-day cells. These observations suggest (i) that the greater adhesiveness to the substrate of the 16-day cells might be due to the presence on the cell surface of a larger amount of glycosaminoglycans at 16 days than at 8 days, and (ii) that the increased accumulation of hyaluronic acid on the cell surface might be involved in an alteration in the cell membrane during differentiation.
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PMID:Inaccessibility of certain Ricinus lectin binding sites due to the increase in hyaluronic acid during chick embryo development. 668 62

Using the sialic acid-specific lectin, limulin (LPA; from Limulus polyphemus hemolymph), the distribution and nature of sialoglycoconjugates on the surface of rat pancreatic cells has been investigated. Binding of rhodaminated LPA (Rh-LPA) or horseradish peroxidase-conjugated LPA (HRP-LPA) to fixed-frozen sections of adult rat pancreas resulted in intense linear staining of the apical surface of acinar cells with fainter staining on the basal but not the lateral cell surfaces. LPA binding was specific in that it could be abolished by 1) pretreatment of tissue sections with neuraminidase or periodic acid; 2) competition with sialic acid; and 3) incubation in Ca2+ -free buffers. Pretreatment of sections with proteases abolished LPA binding to the apical surfaces of acinar cells and also enhanced LPA binding to the lateral cell surface. Lipid extraction of sections following protease treatment markedly reduced LPA binding to the acinar cell periphery. These results suggest that LPA binding sites on the acinar cell apical surface may be primarily sialoglycoproteins, while those on the basolateral surfaces may consist in part of gangliosides. Electron microscopy of collagenase-dispersed acini exposed to HRP-LPA confirmed binding of LPA to the basal plasmalemma and, in addition, revealed staining of basal lamina when present. LPA binding to the acinar cell surface was not affected by digestion of tissue sections with hyaluronidase, heparinase, collagenase, or 6 M guanidine-HCl. Control experiments indicated that rat pancreatic secretory proteins contain undetectable amounts of sialoglycoproteins and thus that the apical localization of LPA is not due to adherent secretory proteins. Islets of Langerhans were always uniformly and heavily stained with LPA conjugates; this staining was protease insensitive. Appearance of LPA binding sites was examined on embryonic pancreatic epithelia. At day 15 of gestation, Rh-LPA stained the entire periphery of the epithelial cells, including the lateral cell surface, although more intense staining was already noted on the apical surface. This pattern persisted through day 17 of gestation, but by day 19 an adult staining pattern was observed with loss of staining of the lateral cell surfaces.
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PMID:Distribution of sialoglycoconjugates on acinar cells of the mammalian pancreas. 675 68

The aim of this study was to evaluate the differential localisation of glycoconjugates of bovine hyaline cartilage matrix by lectin histochemistry, to compare the results of lectin histochemistry with those that can be obtained in the same tissue with PAS and alcian blue. Frozen and paraffin sections were stained with HE, PAS and alcian blue (pH 1.8). Alcian blue staining was carried out also after 1 and 24 hour digestion with bovine testicular hyaluronidase. Peroxidase conjugated WGA, PNA and RS lectins were tested on all sections before and after 1 hour digestion with bovine testicular hyaluronidase. The results show that all the lectins used in this study react with sugars linked to proteoglycans of territorial matrix, the reaction being increased in territorial, and induced in interterritorial matrix by 1 hour hyaluronidase digestion. Alcian blue at pH 1.8 and PAS were complementary, the former staining territorial, and the latter interterritorial matrix. After 1 hour hyaluronidase digestion, alcian blue stained also the interterritorial matrix. These results suggest that lectins react with low molecular weight proteoglycans and that short hyaluronidase digestion causes depolymerization of high molecular weight proteoglycans without loss of their glucidic components, allowing: a) penetration of alcian blue molecules into the macromolecular proteoglycan network; b) an increase of sugar residuals available for lectin histochemistry. Lectin histochemistry can be useful for differential localisation of glycoconjugates in bovine cartilage, especially if associated with short hyaluronidase digestion and conventional histochemical techniques.
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PMID:Lectin binding properties of bovine resting cartilage. 754 42

Neurons in the human visual cortex were demonstrated to possess an intensely negatively charged surface coat which was stained with cationic iron colloid and aldehyde fuchsin. Digestion with hyaluronidase eliminated both the iron colloid and fuchsin stainings of the coats. Treatment with chondroitinase ABC, heparitinase and keratanase eliminated the iron colloid staining of the coats, but did not interfere with the fuchsin staining. Electron microscopy of ultrathin sections revealed that the cationic iron particles were preferentially deposited in the perineuronal tissue spaces. These findings indicate that the surface coats consist of sulfated proteoglycans, which, as an extracellular matrix, occupy the perineuronal tissue spaces. This study further demonstrates that neurons with such surface coats are identical with neurons labeled with lectin Vicia villosa agglutinin. The cell surface glycoproteins reactive to this lectin may not be the structural elements of the sulfated coats since the lectin labeling was not interrupted by the hyaluronidase digestion.
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PMID:Neurons with intensely negatively charged extracellular matrix in the human visual cortex. 773 78

Previous studies have suggested that mucin gene expression is tissue-specific; however, the relationship between unique mucin gene products and the biochemical properties of mucins is unknown. The purpose of this study was to determine the biochemical and molecular characteristics of mucin synthesized by adenocarcinoma cell lines derived from breast (ZR-75-1), stomach (MGC-803), pancreas (Capan-2), and lung (Chago K-1). Mucin was quantitated by [3H]glucosamine labeling and Sepharose CL-4B chromatography. The mucinous nature of the labeled high molecular weight glycoproteins (HMG) was verified by alkaline borohydride treatment, cesium chloride density gradient ultracentrifugation, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Specific mucin gene expression was determined using cDNA probes for 2 distinct intestinal mucins (MUC-2 and MUC-3) and one breast cancer mucin (MUC-1). Specific core mucin proteins were confirmed by immunoblots using antibodies that recognize MUC-1, MUC-2, and MUC-3 core peptides. These experiments demonstrate that all cell lines contained HMG in the medium, cytosol, and membrane fractions. The HMG was mucinous in breast, pancreatic, and lung cell lines. In contrast, most of the HMG secreted by the gastric cell line was proteoglycan-like, due to its susceptibility to hyaluronidase, heparinase, and chondroitinase avidin-biotin complex. Ion-exchange (DEAE-Sephacel) chromatography of [3H]glucosamine-labeled HMG demonstrated that the acidic or basic nature of the mucin was different in all cancer cell lines tested. Despite these differences, mRNA and immunoblot analysis suggest that all cell lines predominantly express MUC-1 apomucin, small amounts of MUC-2 apomucin, and no MUC-3. Immunoprecipitation of MUC-1-type mucin using the 139H2 monoclonal antibody demonstrated that different sizes of mucin peptides were present in all cell lines, corresponding to the known length polymorphism of this mucin. The amount and nature of carbohydrate epitopes were analyzed by immunoblots using anti-T (peanut lectin), anti-Tn (91S8 monoclonal antibody), and anti-sialosyl Tn (JT10e monoclonal antibody). T and Tn antigens were significantly higher in breast and pancreatic cells as compared with lung and gastric cell lines. These findings correlated with increased activities of polypeptidyl N-acetylgalactosaminyl transferase and beta-1,3-galactosyltransferase.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Mucin synthesis and secretion in various human epithelial cancer cell lines that express the MUC-1 mucin gene. 844 22

Distribution of complex carbohydrates in the peripheral and central nervous systems was investigated cytochemically with a lectin that binds specifically to terminal alpha GalNAc and with monoclonal antibodies against carbohydrate epitopes, including glucuronic acid 3-SO4 and chondroitins 6-SO4 and 4-SO4. Comparative staining with these methods differentiated and partially characterized several glycoconjugates in various sites and allowed a comparison of chemical heterogeneity to neural specialization. Distal terminals of sensory neurons concerned with hearing, balance, taste, touch, and sight expressed glucuronyl 3-SO4, which apparently was present in an undefined glycoprotein. Some neurons in sensory nuclei of the brainstem exhibited a similar constituent on their surfaces. Retinal rod outer segments and the cerebellar granular layer possessed masked glucuronyl 3-SO4 that became immunopositive after digestion with chondroitinase ABC and that occurred in chondroitin 6-SO4 and chondroitin 4-SO4, respectively. The surface of neurons in the eighth nerve root and in neighboring nodes of Ranvier stained for unmasked glucuronic acid 3-SO4 and chondroitin 6-SO4. Some neurons of the cerebral cortex expressed unmasked glucuronyl 3-SO4, chondroitin 6-SO4, and terminal alpha GalNAc on their surfaces. Certain cortical neurons and nerve tracts with chondroitin 6-SO4 and terminal alpha GalNAc lacked glucuronyl 3-SO4, and other neurons possessing chondroitin 6-SO4 failed to express either glucuronyl 3-SO4 or terminal alpha GalNAc. Lability of lectin affinity to hyaluronidase suggested the presence of terminal alpha GalNAc in the chondroitin 6-SO4 on cortical neurons. The findings document further the heterogeneity of neural glycoconjugates, expand knowledge about the diversity of neurons with respect to their content of partially characterized glycoconjugates, and link glucuronyl 3-SO4 with or without chondroitin 6-SO4 spatially to sites of active Na+ transport in sensory nerves.
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PMID:Differentiation of glycoconjugates localized to sensory terminals and selected sites in brain. 882 66

Neurons of intracerebellar nuclei in the mouse brain were demonstrated to possess a marked surface coat, formed 3-4 weeks after birth, which was stainable with cationic iron colloid or aldehyde fuchsin. Neurons with a similar surface coat were noted as relay or local interneurons in rather restricted areas such as the occipital cortex, retrosplenial cortex, zona incerta, hippocampal subiculum and spinal posterior horn. Dark neurons with condensed cytoplasm were also shown to be covered with the surface coat. The surface coat was stained doubly with cationic iron colloid and aldehyde fuchsin. Digestion with hyaluronidase eliminated the stainability of the surface coat to both agents. Combined digestion with chondroitinase ABC, heparitinase and keratanase eliminated the cationic iron colloid staining of the surface coat, but did not interfere with the aldehyde fuchsin staining of the surface coat. Electron microscopy of ultrathin sections revealed that the iron particles indicating sulfated proteoglycans were preferentially deposited in the perineuronal tissue spaces. Many neurons in the hippocampal subiculum possessed cell surface glycoproteins which were labeled with lectin Vicia villosa or soybean agglutinin and formed 1-2 weeks after birth. Double staining revealed that these lectin-labeled neurons were identical in part with the neurons reactive to the cationic iron colloid. Dark neurons began to appear 3-4 weeks after birth. The formation of perineuronal sulfated proteoglycans and the appearance of dark neurons, both occurring during the weaning period, may reflect the morphological and physiological completion of the brain. Dark neurons are suggested to be exhausted cells that are restored to light or normal neurons after sleep.
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PMID:Perineuronal sulfated proteoglycans and dark neurons in the brain and spinal cord: a histochemical and electron microscopic study of newborn and adult mice. 884 37


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