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)

Ruthenium red and toluidine blue O precipitates were described associated with lathyritic elastic fibers in aortas of chickens treated with beta-aminopropionitrile fumarate (I. Pasquali-Ronchetti, C. Fornieri, I. Castellani, G. M. Bressan, and D. Volpin (1981). Alterations of the connective tissue components induced by beta-aminopropionitrile. Exp. Mol. Pathol. 35, 42-56). In this report evidence is given that these precipitates reveal the presence of proteoglycans, as they are completely removed by 5 M guanidine-HCl incubation and by specific enzymatic digestions. In particular, proteoglycans associated with the poorly cross-linked lathyritic elastin can be removed by testicular hyaluronidase, chondroitinase ABC, heparitinase, and nitrous acid treatments, whereas they are rather resistant to streptococcal hyaluronidase and chondroitinase AC. On the contrary, proteoglycans of the matrix or associated with collagen fibers are particularly sensitive to these latter enzymatic treatments. The conclusion is reached that glycosaminoglycans associated with beta-aminopropionitrile-induced lathyritic elastin (i) are different from those of the matrix or associated with collagen, and (ii) include mainly dermatan and heparan sulfates.
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PMID:Elastin fiber-associated glycosaminoglycans in beta-aminopropionitrile-induced lathyrism. 670 93

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

1. Primary cultures of chondrocytes from the Swarm rat chondrosarcoma were labelled with either [3H]glucosamine or [14C]glucosamine, and hyaluronate synthesized by the cells was isolated from the cell layer. Parallel cultures were labelled with either [3H]serine or [3H]lysine, and identical fractions were isolated from the cell layer. Some cultures were dual-labelled. 2. In cultures labelled with [3H]serine for between 30 min and 24 h and extracted with 4.0 M-guanidine, a procedure that solubilizes predominantly extracellular macromolecules, small amounts of [3H]serine-labelled molecules were found associated with the hyaluronate fraction purified from the extract by dissociative CsCl-density-gradient centrifugation and dissociative Sepharose CL-2B chromatography. About 75% of the [3H]serine-labelled molecules in the fraction were specifically associated with hyaluronate, since they could be removed by prior treatment with proteinase-free Streptomyces hyaluronidase. The association of the [3H]serine-labelled molecules with hyaluronate was non-covalent, since they could be separated from it by further centrifugation in CsCl density gradients containing 4 M-guanidinium chloride and a zwitterionic detergent. 3. In other experiments the cultures were extracted with a sequential zwitterionic-detergent/guanidinium chloride procedure that completely solubilized the cell layer and enabled fractions containing newly synthesized cell-associated hyaluronate to be isolated. Zwitterionic detergent was present throughout. No [3H]lysine was incorporated into these fractions, irrespective of whether the cultures were pulsed concurrently with [3H]lysine and [14C]glucosamine or sequentially with [3H]lysine to prelabel the protein pool (24 h) followed by [14C]-glucosamine to label hyaluronate (1 h). 4. The results show that newly synthesized hyaluronate is not associated with covalently bound protein, and suggest that chain synthesis is initiated by a mechanism other than on to a core protein. Small amounts of [3H]serine-labelled molecules are, however, non-covalently associated with extracellular hyaluronate. Their identity is at present unknown, but they are probably of low molecular weight.
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PMID:Absence of covalently linked core protein from newly synthesized hyaluronate. 681 60

The synthesis of hyaluronic acid by cultured chondrocytes from the Swarm rat chondrosarcoma was examined using [3H]glucosamine as a precursor. [3H]Hyaluronate in samples was estimated as the specific unsaturated disaccharide released by incubation with chondroitinase ABC under conditions where all [3H]hyaluronate was converted to disaccharide even in the presence of excess chondroitin sulfate. The products of digestion of chondroitin sulfate and hyaluronate were well separated by cellulose thin layer chromatography. A second method involving quantitation of the 3H-oligosaccharides released by digestion with Streptomyces hyaluronidase gave nearly identical results. [3H]Hyaluronate formed about 12% of the [3H]glycosaminoglycans synthesized by the chondrocytes, although levels as high as 20% were found in one set of cultures. The incorporation of [3H]glucosamine into chondroitin sulfate and hyaluronate was linear and at a constant ratio over a 24-h period. The distributions of [35S]proteoglycans, [3H]chondroitin sulfate, and [3H]hyaluronate between the medium, a 4.0 M guanidine HCl extract of the cell layer, and the cell residue, were investigated over 24 h. Both hyaluronate and proteoglycan accumulated in the medium with little retention in the cell layer. Pulse-chase experiments indicated that a greater proportion of the [3H]hyaluronate than the [3H]chondroitin sulfate was initially retained in the cells, but that subsequently [3H]hyaluronate accumulated more rapidly in the medium, suggesting differences in the transit time through the extracellular matrix for the two molecules once secreted from the cell. In cultures labeled for 6 h, 4.0 M guanidine HCl extracted 66% of the hyaluronate and 58% of the chondroitin sulfate associated with the cell layer, while 1% Zwittergent, a zwitterionic detergent, extracted 59% and 29%, respectively. The selective extraction with detergent suggests that there is a pool of hyaluronate in the cell layer which is not associated with proteoglycan aggregates. Equilibrium density gradient centrifugation of cell layer extracts and culture media, under dissociative conditions, showed that 89% of the [3H]hyaluronate banded at densities between 1.43-1.55 g/ml with a peak at 1.47 g/ml. Disaccharide analyses of the gradient fractions showed that the main proteoglycan component contained primarily chondroitin 4-sulfate but also revealed a minor proteoglycan at lower densities which was considerably enriched in chondroitin 6-sulfate.
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PMID:Biosynthesis of hyaluronic acid in cultures of chondrocytes from the Swarm rat chondrosarcoma. 706 20

Monospecific antibodies to bovine cartilage proteoglycan monomer (PG) and link protein (LP) have been used with immunoperoxidase electron microscopy to study the distribution and organization of these molecules in bovine articular cartilage. The following observations were made: (a) The interterritorial matrix of the deep zone contained discrete interfibrillar particulate staining for PG and LP. This particulate staining, which was linked by faint bands of staining (for PG) or filaments (for LP), was spaced at 75- to 80-nm intervals. On collagen fibrils PG was also detected as particulate staining spaced at regular intervals (72 nm), corresponding to the periodicity of collagen cross-banding. The interfibrillar PG staining was often linked to the fibrillar PG staining by the same bands or filaments. The latter were cleaved by a proteinase-free Streptomyces hyaluronidase with the removal of much of the interfibrillar lattice. Since this enzyme has a specificity for hyaluronic acid, the observations indicate that the lattice contains a backbone of hyaluronic acid (which appeared as banded or filamentous staining) to which is attached LP and PG, the latter collapsing when the tissue is fixed, reacted with antibodies, and prepared for electron microscopy. Thishyaluronic acid is anchored to collagen fibrils at regular intervals where PG is detected on collagen. PG and LP detected by antibody in the interterritorial zones are essentially fully extractible with 4 M guanidine hydrochloride. These observations indicated that interfibrillar PG and LP is aggregated with HA in this zone. (b) The remainder of the cartilage matrix had a completely different organization of PG and LP. There was no evidence of a similar latticework based on hyaluronic acid. Instead, smaller more closely packed particulate staining for PG was seen everywhere irregularly distributed over and close to collagen fibrils. LP was almost undetectable in the territorial matrix of the deep zone, as observed previously. In the middle and superficial zones, stronger semiparticulate staining for LP was distributed over collagen fibrils. (c) In the superficial zone, reaction product for PG was distributed evenly on collagen fibrils as diffuse staining and also irregularly as particulate staining. LP was observed as semiparticulate staining over collagen fibrils. The diffuse staining for PG remained after extraction with 4 M guanidine hydrochloride. (d) In pericellular matrix, most clearly identified in middle and deep zones, the nature and organization of reaction product for PG and LP were similar to those observed in the territorial matrix, except that LP and PG were more strongly stained and amorphous staining for both components was also observed. (e) This study demonstrates striking regional variations of ultrastructural organization of PG and LP in articular cartilage...
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PMID:An immunoelectron microscope study of the organization of proteoglycan monomer, link protein, and collagen in the matrix of articular cartilage. 711 5

Proteoglycans were extracted from bovine flexor digitorum profundus tendon (FDP) with 4 M-guanidine hydrochloride in the presence of proteinase inhibitors and purified by density-gradient centrifugation and ion-exchange chromatography. Tendon proteoglycans were fractionated into two major components, D1 and D2, and characterized by chemical analysis and enzymatic (chondroitinases and hyaluronidase) degradations. The two proteoglycans differ with respect to the structure of their glycan side chains; D1 chains were mainly chondroitinsulfate, whereas D2 contained 40% of dermatansulfate. In both proteoglycans keratansulfate chains are probably present. Tendon proteochondroitinsulfate was of larger size than proteodermatansulfate as judged by gel-chromatography on Sepharose 2B. Proteoglycan-collagen interactions were studied by affinity-chromatography on Sepharose 4B-collagen. Both proteochondroitinsulfate and proteodermatansulfate were resolved in two components, with different affinity for collagen. In proteodermatansulfate the component at higher affinity was predominant.
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PMID:Isolation and characterization of two proteoglycans from bovine tendon. 712 59

Articular cartilage function depends on the molecular composition and structure of its extracellular matrix (ECM). The collagen network (CN) provides cartilage with tensile integrity, but must also remodel during growth. Such remodeling may depend on matrix molecules interacting with the CN to modulate the tensile behavior of cartilage. The objective of this study was to determine the effects of increasingly selective matrix depletion on tensile properties of immature and mature articular cartilage, and thereby establish a framework for identifying molecules involved in CN remodeling. Depletion of immature cartilage with guanidine, chondroitinase ABC, chondroitinase AC, and Streptomyces hyaluronidase markedly increased tensile integrity, while the integrity of mature cartilage remained unaltered after depletion with guanidine. The enhanced tensile integrity after matrix depletion suggests that certain ECM components of immature matrix serve to inhibit CN interactions and may act as modulators of physiological alterations of cartilage geometry and tensile properties during growth/maturation.
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PMID:Articular cartilage tensile integrity: modulation by matrix depletion is maturation-dependent. 1839 22

Clinically, amniotic membrane (AM) suppresses inflammation, scarring, and angiogenesis. AM contains abundant hyaluronan (HA) but its function in exerting these therapeutic actions remains unclear. Herein, AM was extracted sequentially with buffers A, B, and C, or separately by phosphate-buffered saline (PBS) alone. Agarose gel electrophoresis showed that high molecular weight (HMW) HA (an average of approximately 3000 kDa) was predominantly extracted in isotonic Extract A (70.1 +/- 6.0%) and PBS (37.7 +/- 3.2%). Western blot analysis of these extracts with hyaluronidase digestion or NaOH treatment revealed that HMW HA was covalently linked with the heavy chains (HCs) of inter-alpha-inhibitor (IalphaI) via a NaOH-sensitive bond, likely transferred by the tumor necrosis factor-alpha stimulated gene-6 protein (TSG-6). This HC.HA complex (nHC*HA) could be purified from Extract PBS by two rounds of CsCl/guanidine HCl ultracentrifugation as well as in vitro reconstituted (rcHC*HA) by mixing HMW HA, serum IalphaI, and recombinant TSG-6. Consistent with previous reports, Extract PBS suppressed transforming growth factor-beta1 promoter activation in corneal fibroblasts and induced mac ro phage apoptosis. However, these effects were abolished by hyaluronidase digestion or heat treatment. More importantly, the effects were retained in the nHC*HA or rcHC*HA. These data collectively suggest that the HC*HA complex is the active component in AM responsible in part for clinically observed anti-inflammatory and anti-scarring actions.
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PMID:Biochemical characterization and function of complexes formed by hyaluronan and the heavy chains of inter-alpha-inhibitor (HC*HA) purified from extracts of human amniotic membrane. 1949 Nov 1


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