Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.36 (hyaluronidase)
 4,606 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. Human embryonic lung and skin fibroblasts were allowed to incorporate 32SO42- or 35SO42- and D-[1-3H]glucosamine. After removal of the medium the monolayer was subjected to sequential extractions by using EDTA, brief trypsin digestion, extraction with dithiothreitol ofllowed by freeze--thawing and extraction with trichloroacetic acid. The heparan sulphate and galactosaminoglycan contents of the various extracts were estimated after deaminative cleavage of the former component. Heparan sulphate was the major component of the trypsin digest, whereas galactosaminoglycans were the dominant component of other fractions. 2. Galactosaminoglycans of the various fractions were subjected to chemical (periodate oxidation/alkaline elimination) and enzymic (chondroitinase-AC and -ABC, as well as testicular hyaluronidase) degradations. Galactosaminoglycans from the insoluble cell fraction and the dithiothreitol extract contained larger amounts of L-iduronic acid than did those of other fractions. 3. Pulse-chase experiments were performed with and without replating of the cells at the start of the chase period. Radioactive glycans were isolated from the various extracts during the chase period. The half-lives of glycans of the insoluble cell fraction and the dithioreitol extract were shorter (5--8h) than were those of the trypsin digest and the EDTA extract (22h and 11h respectively). After replating of the cells in chase medium, radioactive cell-associated glycans were secreted from the cells and could be recovered in the trypsin digest, the EDTA extract and the medium. Furthermore, 35S/3H ratios of glycans from all these fractions decreased during the chase period. The following conclusions were reached. The insoluble cell fraction contains the synthesis pool and some structural material, whereas the soluble cell fraction is the storage and degradation pool. The dithiothreitol extract appears to contain the immediate precursors of secreted material. The trypsin-released glycans comprise structural components as well as material destined for pinocytosis or secretion into the medium. The EDTA extract is considered to consist of glycans en route to the medium. 4. The two presumptive precursor pools were preferentially depleted of L-iduronic acid-rich galactosaminoglycans during the chase. Glycans recovered from the trypsin digest, the EDTA extract and the medium during the chase contained larger amounts of periodate-resistant uronic acid residues (D-glucuronic acid and/or L-iduronic acid O-sulphate) than did their precursors. It is proposed that polymer-level modifications of secreted glycans are partly responsible for the results.
 ...
PMID:Structure and metabolism of sulphated glycosaminoglycans in cultures of human fibroblasts. Structural characteristics of co-polymeric galactosaminoglycans in sequential extracts of fibroblasts during pulse-chase experiments. 22 Sep 58

Collagenase, hyaluronidase, and trypsin were used to isolate single cells from the avian salt gland. Three cell types were distinquishable in the resultant cell suspension: peripheral, intermediate, and principal cells. The fine structure of these cells is described and related to the morphology of the intact gland.
 ...
PMID:The isolation of single cells from the avian salt gland. 22 88

When normal or SV40-transformed Balb/c 3T3 cells are treated with the Ca++-specific chelator EGTA, they round up and pull away from their footpad adhesion sites to the serum-coated tissue culture substrate, as shown by scanning electron microscope studies. Elastic membranous retraction fibers break upon culture agitation, leaving adhesion sites as substrate-attached material (SAM) (Cells leave "footprints" of substrate adhesion sites during movement by a very similar process.) SAM contains 1-2% of the cell's total protein and phospholipid content and 5-10% of its glucosamine-radiolabeled polysaccharide, most of which is glycosaminoglycan (GAG). By one- and two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis, there is considerable enrichment in SAM for specific GAGs; for the glycoprotein fibronectin; and for the cytoskeletal proteins actin, myosin, and the subunit protein of the 10 nm-diameter filaments. Fibrillar fibronectin of cellular origin and substratum-bound fibronectin of serum origin (cold-insoluble globulin, CIg) have been visualized by immunofluorescence microscopy. The GAG composition in SAM has been examined under different cellular growth and attachment conditions. Heparan sulfate content correlates with glycopeptide content (derived from glycoprotein). Newly attaching cells deposit SAM with principally heparan sulfate and fibronectin and little of the other GAGs. Hyaluronate and chrondroitin proteoglycans are coordinately deposited in SAM as cells begin spreading and movement over the substrate. Cells attaching to serum-coated or CIg-coated substrates deposited SAM with identical compositions. The proteoglycan nature of the GAGs in SAM has been examined, as well as the ability of proteoglycans to form two classes of reversibly dissociable "supramolecular complexes" - one class with heparan sulfate and glycopeptide-containing material and the second with hyaluronate-chondroitin complexes. Enzymatic digestion of "intact" SAM with trypsin or testicular hyaluronidase indicates that (1) only a small portion of long-term radiolabeled fibronectin and cyto-skeletal protein is bound to the substrate via hyaluronate or chondroitin classes of GAG; (2) most of the fibronectin, cytoskeletal protein and heparan sulfate coordinately resist solubilization; and (3) newly synthesized fibronectin, which is metabolically labile in SAM, is linked to SAM by hyaluronate- and/or chondroitin-dependent binding. All of our studies indicate that heparan sulfate is a direct mediator of adhesion of cells to the substrate, possibly by binding to both cell-surface fibronectin and substrate-bound CIg in the serum coating; hyaluronate-chondroitin complexes in SAM appear to be most important in motility of cells by binding and labilizing fibronectin at the periphery of footpad adhesions, with subsequent cytoskeletal disorganization.
 ...
PMID:Fibronectin and proteoglycans as determinants of cell-substratum adhesion. 23 21

The concanavalin A (Con A)-induced agglutinability of normal, preneoplastic, and neoplastic mouse mammary epithelial cells was examined. Cells freshly dissociated from normal mammary glands, hyperplastic alveolar nodules, or primary mammary adenocarcinomas by collagenase digestion in the presence of bovine serum albumin were strongly agglutinated by low concentrations of Con A. After short-term culture in vitro, however, cells from all three types of tissue were only weakly agglutinated by Con A, as measured by both suspension and hemadsorption assays. By comparison, cells of three established mammary tumor culture lines agglutinated strongly in the presence of the lectin. Treatment of the normal, preneoplastic, and neoplastic mammary cells in primary cultures with either trypsin or collagenase had little or no effect on their agglutinability, whereas hyaluronidase significantly increased their reactivity. Studies with fluorescein-tagged Con A indicated that all three cell types were capable of binding the lectin. The results were consistent with previous evidence suggesting that neoplastic transformation of mouse mammary epithelial cells is not manifested in vitro by several of the alterations in growth patterns, intercellular interactions, and surface properties that usually accompany transformation of fibroblastic cells.
 ...
PMID:Concanavalin A-induced agglutinability of normal, preneoplastic, and neoplastic mouse mammary cells. 28 51

The adherence of group A streptococci to epithelial cells was studied by using streptococcal strains labeled with [(3)H]uridine or fluorescein isothiocyanate. The ability of the labeled organisms to adhere to Detroit 562 epithelial cells, derived from a human pharyngeal carcinoma, as well as to epithelial cells scraped from the oral cavity was determined. Adherence to monolayer cultures or cell suspensions of Detroit cells compared favorably with adherence to suspensions of human oral epithelial cells. Initial experiments to determine the optimal conditions for adherence showed that adherence was temperature dependent and that the optimal incubation time was 15 min for adherence to epithelial cells in suspension and 30 to 60 min for monolayer cultures. Both streptococci and epithelial cells exhibited specificity in the adherence process. Different streptococcal strains varied in their ability to adhere. Adherence was also affected by the growth stage of the bacterial cultures. Trypsin treatment of the streptococci slightly decreased adherence, whereas hyaluronidase treatment increased the adherence of some strains. Streptococci were found to adhere to only about half of the epithelial cells. Those epithelial cells apparently have a limited number of receptor sites since they can be saturated by adding increasing concentrations of bacteria. Further support for limited receptor sites was provided by competition experiments. Adherence was inhibited by trypsin treatment of the epithelial cells, suggesting that proteins in the epithelial cell membrane may play a role in streptococcal adherence.
 ...
PMID:Adherence of group A streptococci to human epithelial cells. 35 28

Transfer of radioactive materials to fixed cells from an overlying layer of living cells has been examined to determine whether fixed cells can act as acceptors of glycosyltransferases of living cells. After the incubation of living cells were removed by EDTA treatment, and the radioactivity associated with the fixed cells was determined. Lipids, proteins and carbohydrates were found to be transfered from the living cells to the fixed cells. The amount of radioactivity transferred to the fixed cells was dependent on the number of both fixed and living cells and increased with the time of incubation. When fixed cells were treated with chloroform-methanol before the addition of living cells, the transfer of both lipids and proteins to the fixed cells decreased drastically, but only a slight decrease incarbohydrate transfer was observed. Most of the radioactive materials transferred from living cells labeled with glucosamine or fucose to chloroform-methanol-treated fixed cells were solubilized by trypsin but not by the detergents tested. Approximately 55% of the materials transferred from the cells labeled with glucosamine could be solubilized by hyaluronidase and chondroitinase, and the rest was solubilized by neuraminidase and a glycosidase mixture. The treatment of chloroform-methanol-extracted fixed cells with trypsin caused a significant decrease in the transfer from cells labeled with glucosamine. When nucleotide sugars were used as the radioactive precursor, no significant amount of radioactivity was transferred to the fixed cells.
 ...
PMID:Cellular interaction between fixed and living cells. Transfer of radioactive materials from living cells to fixed cells. 37 19

Russian investigators have recently reported clinical recovery of enzyme treated, spinal cord transected rats. Using the exact protocols of Matinian and Andreasian's two most successful treatment regimens, we repeated their experiments using United States produced pure hyaluronidase and trypsin or trypsin and elastase. Animals were evaluated for return of bladder function, clinical evidence of hind limb motor function, cortical evoked response after sciatic nerve stimulation, and axonal transport of cortically injected tritiated proline by regenerated corticospinal axons. None of the treated animals differed from control animals treated only with the enzyme vehicle. No animals walked, had return of voluntary motor activity, showed cortical evoked response, or had evidence for transport of tritiated proline over regenerated corticospinal axons.
 ...
PMID:Enzyme treatment of spinal cord transected rats. 42 86

Cell responses to different natural substrates have been followed by scanning microscopy in order to evaluate the role of these substrates in morphogenesis. Matrix has been isolated then repopulated with suspensions of embryonic cells from chick skin, spinal ganglia, duodenal epithelium and heart. In some cases outgrowth from amphibian embryonic tissue was used. Basal lamina of the Xenopus tail may be exposed by freezing and thawing the tissue, or by EDTA treatment. The underlying lamella of orthogonally oriented collagen fibers may be exposed by use of trypsin or hyaluronidase. Trypsin causes more clumping of collagen fibers and a coarser texture of the matrix. On trypsin isolated basement lamella, nerve cell processes grow out on the surface and show no strong tendency to penetrate the lamella while skin mesenchymal cells commonly burrow among the collagen plies. Epithelial cells remain on the surface. On the basal lamina mesenchymal cells ruffle in early stages of culture, then flatten. Epithelial cells flatten rapidly on the lamina. These differences in cell response are in some cases closely related to cell behavior in vivo and suggest that cells show a selective response to the chemical composition of the substrate as well as to its physical conformation.
 ...
PMID:Differential response of embryonic cells to culture on tissue matrices. 45 99

Soluble 125I-labeled type I collagen binds to cultured fibroblasts but not to cultured epithelia. The binding of the ligand to fibroblasts is reversible, saturable and highly specific for sequences contained within the helical portions of the alpha1 and alpha2 chains. The amount of ligand bound is dependent upon cell number and ligand concentration. Binding is decreased but measurable at 4 degrees C. The steady state binding is greater at 26 degrees than at 37 degrees C due to a more rapid dissociation of the ligand-acceptor complex at 37 degrees C. The half-life of the complex is 46 min at 37 degrees C and approximately 2.5 hr at 26 degrees C. Scatchard plots of binding data indicate a single class of high affinity binding sites (KD = 1.2 X 10(-11) M) with each fibroblast binding approximately 500,000 molecules at saturation. Pretreatment of fibroblasts with bacterial collagenase, chondroitinase ABC or testicular hyaluronidase does not affect the binding reaction, whereas pretreatment of the cells with phospholipase C increases the amount of ligand bound. Ligand binding is decreased but not abolished after fibroblasts are treated with trypsin concentrations which remove surface fibronectin. Fibroblast monolayers treated with antiserum against fibronectin bind the radiolabeled ligand normally. In contrast to collagen, addition of excess fibronectin does not accelerate the dissociation of bound ligand from fibroblasts. Possible functions for surface-bound collagen are discussed.
 ...
PMID:Binding of soluble type I collagen molecules to the fibroblast plasma membrane. 45 36

Erythrocytes of different species (chicken, sheep, man, mouse, rat, guinea pig) except rabbit erythrocytes strongly adhere to the marginal zone of mouse spleen follicles in frozen sections. This adherence reaction (AR) is not restricted to red blood cells but is also observed with human lymphocytes. Pretreatment of the tissue sections with trypsin, mercaptoethanol, periodate, chloroform/methanol, acetone, and heating the sections abolishes AR whereas neuraminidase (VCN) treatment of the sections has an amplifying effect. AR is inhibited by preincubation of the neuraminidase- or untreated sections with neuraminic acid (NA). Treatment of the erythrocytes with VCN completely abolishes AR whereas treatment with other enzymes (hyaluronidase, collagenase) is ineffective in this respect. Determination of NA in the erythrocyte membrane before and after VCN treatment reveals a positive correlation between the amount of NA and AR. Rabbit red blood cells have the lowest NA content in their membranes and, in addition, there is little effect of VCN treatment in further reducing it. It is possible that a lectin-like substance is responsible for AR. The biologic significance of AR is hypothetical, but since AR occurs in an area of the spleen playing a role in antigen trapping it is conceivable that this trapping may be mediated by interaction of NA and NA receptor(s).
 ...
PMID:Erythrocyte adherence to the marginal zone of mouse spleen follicle mediated by receptor(s) for neuraminic acid. 46 83


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>