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:3.1.6.4 (chondroitinase)
2,039 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Colony stimulating factor-1 (CSF-1) is a homodimeric glycoprotein that humorally regulates the proliferation and differentiation of mononuclear phagocytic cells and locally regulates cells of the female reproductive tract. Alternative splicing of the human CSF-1 mRNA leads to alternative expression of the CSF-1 homodimer as a secreted glycoprotein or as a membrane-spanning molecule with cell surface biological activity. In the present study, analysis of immunoaffinity-purified CSF-1 from mouse L929 cell medium by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) indicated that CSF-1 is predominantly secreted as highly sulfated species of 375- and 250-kDa with a smaller amount of a 100-kDa species. Analysis by gel filtration in 4 M guanidine HCI buffer, indicated that, in contrast to the 100-kDa species, the highly sulfated species exhibit anomalously high molecular weights and self-association on SDS-PAGE similar to the dermatan sulfate proteoglycan, biglycan. The three predominant CSF-1 species were shown to be an 80-kDa homodimer, an 80-kDa/50-kDa heterodimer, and a 50-kDa homodimer. The 80-kDa subunit contained a single 18-kDa chondroitin sulfate chain that was absent from the 50-kDa subunit. Furthermore, treatment of the 80- and 50-kDa subunits, synthesized in the presence of tunicamycin, with chondroitinase ABC, neuraminidase, and endo-alpha-N-acetyl galactosaminidase reduced their apparent molecular masses to 60 and 25 kDa, respectively. These results are consistent with intracellular proteolytic cleavage of the 80-kDa chondroitin sulfate containing subunits from the membrane spanning CSF-1 precursor at a point carboxyl-terminal to the single consensus sequence for glycosaminoglycan addition and cleavage of the 50-kDa glycoprotein subunit at a position aminoterminal to this site. The predominance of the proteoglycan form of secreted CSF-1, which represents only 3-4% of the total trichloroacetic acid-precipitable counts released from 35SO4(2-)-labeled L cells, has important implications for regulation by this growth factor.
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PMID:The predominant form of secreted colony stimulating factor-1 is a proteoglycan. 173 26

Smooth muscle cells, isolated from rat and bovine aortae and grown in vitro, synthesize chondroitin sulfate proteoglycans which are secreted into the growth media. Analysis of metabolically [35S]-labeled macromolecules, employing ion-exchange chromatography, revealed a single peak of radioactivity, upon elution with a linear salt gradient. Treatment of the material with enzymes that specifically degrade chondroitin sulfate demonstrated that chondroitin-4-sulfate was the predominant species isolated from rat smooth muscle cells and that chondroitin-4-sulfate and dermatan sulfate were the predominant species isolated from bovine aortic smooth muscle cells. Treatment of the native proteoglycans with chondroitinase ABC and subsequent SDS-PAGE analysis of the digestion products resulted in the appearance of a band with an apparent molecular weight of 45,000. Electrotransfer of the core protein to Immobilon-P membrane and gas phase sequencing of the amino-terminal region revealed striking homology between the core proteins of the rat and bovine proteochondroitin with the pre-propeptide region of human bone biglycan.
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PMID:The amino-terminal region of a proteochondroitin core protein, secreted by aortic smooth muscle cells, shares sequence homology with the pre-propeptide region of the biglycan core protein from human bone. 201 13

Proteoglycans (PGs) comprise a group of extracellular matrix macromolecules which play an important role in matrix biology. In this study, normal human skin and gingival fibroblast cultures were incubated with transforming growth factor-beta 1 (TGF-beta 1), and the expression of three PGs, viz. biglycan (PGI), decorin (PGII), and versican (a large fibroblast proteoglycan) was examined. The results indicate that TGF-beta 1 (5 ng/ml) markedly increased the expression of biglycan (up to 24-fold) and versican (up to 6-fold) mRNAs and the enhancement of biglycan expression was coordinate with elevated type I procollagen gene expression in the same cultures. In contrast, the expression of decorin mRNA was markedly (up to approximately 70%) inhibited by TGF-beta 1. The response to TGF-beta 1 was similar in both skin and gingival fibroblasts, although the gingival cells were clearly more responsive to stimulation by TGF-beta 1 with respect to biglycan gene expression. Analysis of 35S-labeled proteoglycans in the culture media of skin and gingival fibroblasts also revealed stimulation of biglycan and versican production, and reduction in decorin production. Quantitation of both [35S]sulfate and [3H]leucine-labeled decorin in cell culture media by immunoprecipitation revealed a 50% reduction in decorin production in cell cultures treated with TGF-beta 1. This TGF-beta 1-elicited reduction was accompanied by an apparent increase in the size of the decorin molecules, although the size of the core protein was not altered, as judged by Western immunoblotting following chondroitinase ABC digestion. Analysis of the proteoglycans in the matrix and membrane fractions also revealed increased amounts of versican in cultures treated with TGF-beta 1. These results indicate differential regulation of PG gene expression in fibroblasts by TGF-beta 1, and these observations emphasize the role of PGs in the extracellular matrix biology and pathology.
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PMID:Differential regulation of extracellular matrix proteoglycan (PG) gene expression. Transforming growth factor-beta 1 up-regulates biglycan (PGI), and versican (large fibroblast PG) but down-regulates decorin (PGII) mRNA levels in human fibroblasts in culture. 203

Accumulation of glomerular extracellular matrix is a prominent feature of most forms of progressive glomerular disease. Since some growth factors may play a role in extracellular matrix production, we examined the effects of transforming growth factor-beta (TGF-beta), interleukin 1, platelet derived growth factor, and tumor necrosis factor on the production of extracellular matrix components by cultured rat mesangial cells. In control experiments we found that mesangial cells produced two distinct proteoglycans identified as the small chondroitin/dermatan sulfate proteoglycans biglycan (PG I) and decorin (PG II) by showing that their mobility on SDS-PAGE changed upon digestion by chondroitinase ABC, and that they reacted with antibodies raised against synthetic peptides from the core protein sequence of human biglycan and decorin. Exposure to TGF-beta for 48 hours stimulated an 8- to 10-fold increase in the biglycan and decorin bands, and induced a structural change detected as a shift in electrophoretic mobility. TGF-beta did not demonstrably affect the production of other matrix proteins by the mesangial cells. The other growth factors tested had no comparable effect on the production of proteoglycans or other extracellular matrix components by these cells. Our results show that TGF-beta is unique among growth factors in its regulatory effects on mesangial cell proteoglycan production. The release or activation of TGF-beta during glomerular injury could mediate the accumulation of proteoglycans in the extracellular matrix and predispose the kidney to development of glomerulosclerosis.
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PMID:Transforming growth factor-beta regulates production of proteoglycans by mesangial cells. 240 84

Proteoglycans were isolated by ion-exchange chromatography from the extracted cell layer and culture medium of human bone cell cultures following incubation in the presence of [35S]sulfate and [3H]leucine. On sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), the synthesized proteoglycans consisted of at least five polydisperse species having median apparent Mr = 600,000, 400,000, 270,000, 135,000 and 40,000. When chromatographed further on octyl-Sepharose CL-4B, the proteoglycans of the cell layer resolved into three peaks. The unbound fraction (peak cell layer-I) contained a 40,000 species consisting of a single glycosaminoglycan chain with or without peptide. Peak cell layer-II contained three sulfated species on electrophoresis: a 600,000 species uniformly distributed across the peak, a 135,000 species enriched in the ascending limb (similar to bone PG-I as described previously), and a 270,000 species (similar to bone PG-I) enriched in the descending limb. Peak cell layer-III, eluting at 0.2% Triton X-100, was highly enriched in a 400,000 proteoglycan component. When media proteoglycans were chromatographed on octyl-Sepharose, two labeled peaks were found. Peak medium-I (unbound) contained a species exhibiting electrophoretic mobility similar to that of the 400,000 species present in peak cell layer-III. Peak II of the culture medium (medium-II) was apparently identical to that of peak cell layer-II, containing the 600,000, 270,000 and 135,000 species. No appreciable 40,000 species was observed in the medium. Treatment of the 600,000 species with either chondroitinase ABC or ACII generated a core protein preparation with bands of 390,000 and 340,000 on SDS gels. Neither the intact nor the chondroitinase ABC-treated 600,000 species was immunoprecipitated by a purified, polyclonal antiserum raised against the core protein of the large chondroitin sulfate proteoglycan of human articular cartilage. Treatment of the 270,000 and 135,000 proteoglycans with chondroitinase ABC, but not ACII, generated a core protein preparation with bands of 52,000 and 49,000 on SDS gels, indicating that they were dermatan sulfate-containing species. The 400,000 species contained both heparan sulfate and chondroitin sulfate, in approximately a 3:1 labeling ratio. This species changed in electrophoretic mobility following treatment with chondroitinase ABC, heparatinase, or both enzymes in combination, which suggested that it may be a hybrid proteoglycan (i.e. both types of glycosaminoglycan chain on the same core protein).(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Analysis of the proteoglycans synthesized by human bone cells in vitro. 368 Feb 94

The structure of adult bovine articular cartilage high density proteoglycans (PG-I) was studied by degradation with Pronase, chondroitinase ABC, and alkaline borohydride treatments and fractionation and analysis of the products. The keratan sulfate (KS) peptides were rich in glutamic acid, proline, and serine and had a low glycine content. The chondroitin sulfate (CS) peptides had a high content of serine, glycine, and glutamic acid and a much lower proline content than the KS peptides. The data indicate that the KS and CS chains occur in more distinct regions of the protein core(s) than in bovine nasal cartilage PG. After alkaline borohydride treatment there was an almost quantitative conversion of xylose to xylitol and galactosaminitol was the only hexosaminitol detected in KS fractions. The results obtained indicated that the alkali-labile bonds linking the CS and KS chains are the same as those reported to occur in other cartilage PGs. The Mr of the KS chains calculated from the glucosamine and galactosaminitol contents gave values of 6,000-7,000, although gel chromatography and light scattering measurements indicated considerable heterogeneity. The KS and CS chains were quantitatively precipitated by cetylpyridinium chloride and the KS and a portion (15%) of the CS chains were found to be soluble in 1% cetylpyridinium chloride. The abnormal solubility properties of the CS chains in the presence of 1% cetylpyridinium chloride is thought to be due to their low sulfate content. The molecular weight of the remainder of the CS chains, based on the ratio of xylitol to galactosamine, varied from 6,500 to 16,000. The low Mr CS chains were rich in 6-sulfated disaccharides whereas the higher Mr chains had a higher content of 4-sulfated disaccharides. The ratio of galactose to xylitol also varied with Mr. These results indicate similarities in the structure of the adult bovine articular cartilage PG-Is to other cartilage high density PGs. The heterogeneities observed in the composition of the KS and CS chains, and their occurrence in relatively distinct regions of the protein core(s) indicate, however, that there is still much to be learned about the structure of these complex macromolecules.
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PMID:On the structure of bovine articular cartilage high density proteoglycans. Isolation of the keratan sulfate and chondroitin sulfate side chains. 623 5

Immunological and biochemical characteristics of a 100,000 MW biglycan-like haemopoietic factor, purified from thymic myoid cells 871207B, were studied to distinguish them from macrophage colony-stimulating factor (M-CSF), which they resemble in activity and biochemical properties. Rabbit antibody raised against a synthetic peptide fragment (J-1) designed from amino acid sequences specific to the 100,000 MW factor responded to 871207B cells, the conditioned medium of 871207B, and capillary-like structures in the thymus, but not to M-CSF producer L-929 cells or the conditioned medium of L-929 cells. In contrast, M-CSF epitope was detected in L-929 cells and the conditioned medium cells but not in 871207B cells or the conditioned medium, even after enzymatic digestion of glycosaminoglycan chains. Treatment of the 100,000 MW factor with chondroitinase ABC and AC produced a 50,000 MW component. Digestion of this product with N-glycanase resulted in a 40,000 MW protein component. These results suggest that the 100,000 MW factor is a proteoglycan consisting of a core protein with an apparent molecular mass of 40,000 MW, a 50,000 MW chondroitin sulphate chain and 10,000 MW N-linked oligosaccharide chains. A small amount of a 40,000 MW monocytic cell growth activity was also found in the 871207B cell-conditioned medium. An enzymatically obtained 40,000 MW factor, the conditioned medium 40,000 MW factor, and the 100,000 MW factor were specifically eluated from an anti-J-1 IgG-immobilized affinity column with monocytic cell growth activity, suggesting that the biological activity resides in the 40,000 MW core protein. The 100,000 MW factor induced the proliferation and differentiation of monocytic lineage cells from a variety of sources, such as bone marrow cells, peritoneal exudated cells and brain microglia cells.
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PMID:Immunological and biochemical characterization of biglycan-like haemopoietic factor. 754 45

Polyclonal anti-peptide antibodies were raised to the C-terminal regions of human biglycan and decorin. These antibodies were used in immunoblotting to study structural variations with age in the proteoglycan core proteins present in extracts of human articular cartilage and intervertebral disc. Three forms of the biglycan core protein were identified. The largest form was detected only after chondroitinase treatment and represents the proteoglycan form of the molecule from which the glycosaminoglycan chains have been removed. However, chondroitinase treatment did not alter the electrophoretic mobility of the two smaller proteins, which appear to represent non-proteoglycan forms of the molecule, resulting either from a failure to substitute the intact proteoglycan core protein with glycosaminoglycan chains during its synthesis or from proteolytic processing of the intact proteoglycan causing removal of the N-terminal region bearing the glycosaminoglycan chains. The non-proteoglycan forms constituted a minor proportion of biglycan in the newborn, but were the major components in the adult. A similar trend was seen in both articular cartilage and intervertebral disc. In comparison, decorin appears to exist predominantly as a proteoglycan at all ages, with two core protein sizes being present after chondroitinase treatment. Non-proteoglycan forms were detected in the adult, but they were always a minor constituent.
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PMID:Non-proteoglycan forms of biglycan increase with age in human articular cartilage. 824 Feb 39

Two small interstitial dermatan sulfate-containing proteoglycans, biglycan and decorin, are present in extracellular matrices of skin, tendon, ligament, and cartilage. We investigated the effects of biglycan and decorin on the inhibition of alpha-thrombin by the serine proteinase inhibitor heparin cofactor II. In solution, heparin cofactor II inhibition of thrombin is accelerated by intact biglycan or decorin and by the dermatan sulfate-containing glycosaminoglycan (GAG) chains prepared from the proteoglycans, while core protein from cartilage biglycan had no effect. L-Iduronic acid-rich skin decorin and GAG chains had a greater accelerating effect than proteoglycan and GAG chains from cartilage that had lower L-iduronic acid content. Treatment of skin decorin and GAG chains with chondroitinase ABC totally eliminated the ability of these compounds to accelerate thrombin inhibition by heparin cofactor II suggesting that dermatan sulfate was responsible for this action. Both biglycan and decorin bound to type V collagen in a saturable and specific manner. Biglycan, decorin, and core protein from biglycan competed for decorin binding to the type V collagen, while only the intact proteoglycans competed for biglycan binding. When bound to type V collagen, both biglycan and decorin accelerated the heparin cofactor II/thrombin inhibition reaction as efficiently as the proteoglycans in solution. Our results demonstrate that heparin cofactor II in the presence of biglycan or decorin bound to type V collagen provides a "thromboresistant surface," further suggesting a physiological function for these proteins in regulating the extravascular activities of thrombin.
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PMID:Interaction of heparin cofactor II with biglycan and decorin. 844 Jun 85

Dermatan sulfate proteoglycans (DSPG) were extracted from intima-media of grossly normal aortic tissue of White Carneau pigeons and were purified by ion exchange chromatography on DEAE-Sephacel followed by size exclusion chromatography on Sepharose CL-4B. The major aortic DSPG had an average size of 310 kDa. The core protein resulting from treatment of the PG with chondroitinase ABC: (1) was found to be approximately 48 kDa by SDS-polyacrylamide gel electrophoresis; (2) was recognized by monoclonal antibody (Mab) 2-B-6 but not by Mab 3-B-3 on Western blots, indicating the presence of delta Di-4S and absence of delta Di-6S; (3) was glycosylated with Asn-linked oligosaccharides; (4) contained a high content of Asx, Glx and Leu, similar to that found for core proteins of this size from other tissues and species and (5) contained an N-terminal sequence (Asp-Glu-Gly-Xaa-Ala-Asp-Met-Pro-Pro-Xaa-Asp-Asp-Pro-Val- Ile-(ile)-Gly-Phe-), which was similar to sequences of DSPG core proteins previously described as 'decorin' and distinct from DSPG described as 'biglycan'. The results suggest that the major DSPG of aorta can be classified as a decorin molecule. The overall size of the DSPG in aorta was larger than decorin molecules described in non-arterial tissues of other species. Evidence is presented to conclude the larger size results from more than one dermatan sulfate-glycosaminoglycan chain.
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PMID:Structural properties and partial protein sequence analysis of the major dermatan sulfate proteoglycan of pigeon aorta. 845 55


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