Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.6.4 (chondroitinase)
 2,039 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Electron microscopy of ruthenium red stained bovine aorta before and after chondroitinase digestion demonstrates proteoglycans on and between collagen fibrils. The collagen-associated proteoglycans include a proteoglycan previously purified from this tissue as demonstrated by immunocytochemistry and are extractable with high molar guanidine HC1. In loci rich in proteoglycans such as areas of turbulent flow in calves, more proteoglycan can be demonstrated morphologically, and these molecules also coat elastin.
 ...
PMID:The ground substance of the arterial wall. Part 2. Electron-microscopic studies. 13 92

Appreciable amounts of glycosaminoglycans have been found by immunocytochemistry within mature elastin fibers of human dermis. On thin sections, elastin fibers showed antigenic sites for monoclonal antibodies recognizing the unsaturated units remaining after digestion of hyaluronic acid with Streptomyces hyaluronidase and after digestion of dermatan and chondroitin sulfates with chondroitinase ABC. Moreover, sectioned elastin fibers were positive towards antibodies raised against synthetic peptides corresponding to amino acid sequences near the N-terminus of the protein core of small matrix proteoglycans PGI and PGII, respectively (Fisher et al., J. Biol. Chem. 262, 9702-9708 (1987)). This is the first demonstration that highly hydrophylic molecules are strictly associated with normally cross-linked elastin. The presence of highly hydrated molecules within the elastin polymer could greatly influence its physiological properties and behavior in pathology.
 ...
PMID:Immunocytochemical localization of proteoglycans within normal elastin fibers. 212 20

By use of the cationic dye Cuprolinic Blue in a critical electrolyte concentration method, heavily staining, generally large, filaments have been demonstrated in human lung alveoli. In some lung specimens they are abundant, while in others they are very scanty. The filaments are seen: around bundles of collagen fibrils, at places which seem electron microscopically almost empty, associated with basement membranes around elastin, and sometimes associated with individual collagen fibrils. After poststaining tiny threads--connecting the filaments--could sometimes be observed. The filaments are resistant to treatment with nitrous acid, heparitinase or pronase after prefixation. After digestion with chondroitinase ABC, chondroitinase AC or pronase without prefixation, the filaments are no longer detectable. The tiny threads are chondroitinase ABC resistant. It is concluded that the Cuprolinic Blue-positive filaments represent proteoglycans which contain chondroitin sulfate and/or glucuronic acid-rich dermatan sulfate. The possible role of these proteoglycans in tissue repair is discussed.
 ...
PMID:Further characterization of a large proteoglycan in human lung alveoli. 242 May 93

A direct Schiff reaction of elastic tissues has been known for many years, but the nature of the native aldehyde-rich components has not been clear. In this study, chicken, quail, and rat embryos and adult rat lung, aorta, and kidney were fixed in methacarn or in a formalin solution, embedded in paraffin, and sections of 8-10 micron obtained. Rehydrated sections were incubated for various periods in solutions of the enzymes chondroitinase ABC, clostripain, collagenase, elastase, heparatinase, hyaluronidase, subtilisin Carlsberg ("protease"), or trypsin, and in solutions of phosphomolybdic acid or sodium borohydride. After incubation, sections were placed, without prior oxidation, in Schiff's reagent, and were ultimately observed and photographed in transmitted light or with blue or green epifluorescence. A Schiff-positive substance was found, always and exclusively, in elastic tissues of the vasculature and lungs, which was hydrolyzed by the proteolytic enzymes to an extent that ranged from complete loss of Schiff reaction in minutes (trypsin) to no loss of Schiff reaction in 22 hr (clostripain). The Schiff-reactive protein preceded the time of appearance of elastin in the early embryos. We conclude that the aldehyde-rich protein responsible for this reaction is a harbinger of elastogenesis in vivo and speculate that it may represent the elastic microfibril or a component thereof.
 ...
PMID:A new interpretation of the direct Schiff reaction of elastic connective tissue. 244 56

An analysis of the structure of chicken vitreous humor after brief homogenization of the tissue was performed. Electron micrographs prepared after rotary shadowing with platinum showed the presence of two distinct fibrils. The collagen fibril was coated by glycosaminoglycan which could be removed by chondroitinase ABC digestion. In addition, individual molecules of tenascin were observed wrapped around some of the collagen fibrils. A second beaded fibril was present and several fine filaments were observed to extend from each bead. The beaded fibril is formed by the overlap of these filaments, and beaded fibrils were observed in either a "closed" or an "open" form dependent on whether all of the filaments are brought together to form the overlap. A schematic diagram is presented for the structure of the beaded fibril. The potential relationship of the beaded fibril to the zonular fibrils and the elastin microfibrils is briefly discussed.
 ...
PMID:Vitreous humor of chicken contains two fibrillar systems: an analysis of their structure. 246 20

Thirteen cases of elastofibroma have been studied by conventional light and electron microscopy, as well as by histochemistry and immunohistochemistry. By light microscopy elastinophilic material appeared as huge fibers crossing collagen bundles. Immunohistochemistry demonstrated a strong positivity for elastin in numerous and circumscribed areas of the extracellular matrix. By electron microscopy, collagen consisted of 40-50-nm wide fibrils, and elastin was made of large aggregates of moderately electron-dense material surrounding a very thin, apparently normal, elastin core. At high magnification these aggregates consisted of short tubules, often in regular arrays, surrounded by microfibrils and microfilaments. These data, associated with selective digestions on thin sections with elastase, purified collagenase, hyaluronidase, and chondroitinase ABC, revealed that elastic fibers in elastofibroma seem to be made of true elastin surrounded by an enormous amount of hydrophilic material, in which some elastin, chondroitin sulfates, and collagenase type-VII sensitive material are aggregated forming a rather ordered array of short tubules.
 ...
PMID:Elastofibroma: an in vivo model of abnormal neoelastogenesis. 284 Jul 67

The localization of lysyl oxidase was examined in calf and rat aortic connective tissue at the ultrastructural level using polyclonal chicken anti-lysyl oxidase and gold conjugated rabbit anti-chicken immunoglobulin G to identify immunoreactive sites. Electron microscopy of calf aortic specimens revealed discrete gold deposits at the interface between extracellular bundles of amorphous elastin and the microfibrils circumferentially surrounding these bundles. The antibody did not react with microfibrils which were distant from the interface with elastin. There was negligible deposition of gold within the bundles of amorphous elastin and those few deposits seen at these sites appeared to be associated with strands of microfibrils. Lysyl oxidase was similarly localized in newborn rat aorta at the interface between microfibrils and nascent elastin fibers. Gold deposits were not seen in association with extracellular collagen fibers even after collagen-associated proteoglycans had been degraded by chondroitinase ABC. However, the antibody did recognize collagen-bound lysyl oxidase in collagen fibers prepared from purified collagen to which the enzyme had been added in vitro. No reaction product was seen if the anti-lysyl oxidase was preadsorbed with purified lysyl oxidase illustrating the specificity of the antibody probe. The present results are consistent with a model of elastogenesis predicting the radial growth of the elastin fiber by the deposition and crosslinking of tropoelastin units at the fiber-microfibril interface.
 ...
PMID:Ultrastructural immunolocalization of lysyl oxidase in vascular connective tissue. 287 77

Skin biopsies from patients with pseudoxanthoma elasticum (PXE) were studied by electron microscopy either before or after selective digestions with collagenase, elastase, trypsin, hyaluronidase, chondroitinase AC and ABC, with the aim of identifying an eventual organic component associated with mineralization within the elastin fibers and the chemical nature of the enormous aggregates of filaments very often associated with, but distinct from mineralized elastin fibers. The results obtained, on both embedded thin sections and fresh tissue fragments, showed that elastin fibers, whether mineralized or not, were sensitive only to elastase, and they did not contain significant amounts of materials different from elastin that could be accounted for by ion precipitation; the aggregates of microfilaments in strict connection with altered elastin fibers were mostly sensitive to elastase and hyaluronidase, were partially removed by trypsin and chondroitinase, and were not modified by collagenase, which seems to indicate that the microfilaments consist mainly of abnormally aggregated elastin molecules together with low sulfated proteoglycans. It may be concluded that PXE is a complex genetic disorder of the connective tissue, and that mineralization of elastin is only one of the alterations of the extracellular matrix.
 ...
PMID:Effect of selective enzymatic digestions on skin biopsies from pseudoxanthoma elasticum: an ultrastructural study. 301 57

In contrast to glutaraldehyde-fixed vascular tissue with or without staining with cationic dye, the nonfibrous extracellular matrix of fast-frozen, freeze-dried rabbit aorta and renal artery contained a continuous reticulum of fine filaments, closely associated with collagen, elastin, and smooth muscle cells. Three morphologically distinct types of filament were distinguished; one type was selectively sensitive to chondroitinase ABC degradation, and therefore contains chondroitin and/or dermatan sulfate. The remaining filaments of the reticulum may represent the protein core of the proteoglycan monomer, and the hyaluronic acid backbone of the aggregate. Filaments associated with the surface of smooth muscle cells were usually linked to a continuous filament parallel to the cell surface, which was degraded by heparitinase and therefore contains heparan sulfate. The filaments linked directly to the cell surface were not degraded by either enzyme. The preservation of PG in fast-frozen material provides a significant improvement over that obtained by any presently available technique.
 ...
PMID:Proteoglycan in fast-frozen, freeze-dried, plastic-embedded rabbit arteries. 337 71

Glycosaminoglycans (GAGs) have been implicated in the pathogenesis of sclerotic vascular disease. The localization of GAGs in the rat aorta was examined by two different ultrastructural cytochemical approaches. These procedures are believed to demonstrate 1) anionic sites, with fixatives that contain either toluidine blue or ruthenium red, both cationic dyes, and 2) polysaccharides, proteoglycans, and glycoproteins, with an osmium--ferrocyanide mixture that binds to vicinal diols. Both procedures stain a network of insoluble, 2--8-nm filaments that bridge collagen fibers, elastin, basement membranes, and plasma membranes. These structures resist digestion with chondroitinase ABC and appear to be identical to the filaments that have previously been demonstrated with ruthenium red. Focal 6--12-nm densities are present where filaments intersect. However, the large granules that are made visible with ruthenium red are not seen in toluidine blue or osmium--ferrocyanide preparations. A soluble and relatively amorphous component surrounds the tightly packed bundles of collagen in the media and is preserved and stained by toluidine blue and osmium--ferrocyanide mixtures.
 ...
PMID:Glycosaminoglycans in the rat aorta. Ultrastructural localization with toluidine blue O and osmium--ferrocyanide procedure. 617 40


1 2 Next >>