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

---

Query: EC:3.5.1.52 (PNGase F)
1,527 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Three glucuronic acid-rich dermatan sulfate proteoglycans (DS-PGs) have been isolated by chromatographic and electrophoretic techniques from cultures of bovine aortic endothelial cells and characterized structurally. The smallest of the DS-PGs (DS-II) has an apparent Mr of approximately 100,000 and glycosaminoglycan chains of Mr approximately 29,000. Core glycoprotein samples prepared by chondroitin ABC lyase digestion run as doublets of Mr = 45,000 and 48,000 on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. A decrease in core size is apparent after N-glycanase digestion, or when DS-PG is isolated from tunicamycin-treated cultures, providing evidence that the core protein is N-glycosylated. Isolated DS-II shows evidence of self-association when subjected to liquid chromatography under conditions of reduced ionic strength, but not during sodium dodecyl sulfate-polyacrylamide gel electrophoresis. In addition, DS-II, but not other endothelial cell DS-PG subclasses, is bound by an antibody against human skin fibroblast DS-PG, indicating that this DS-PG belongs to a family of widely distributed small DS-PGs, previously isolated from various connective tissues. A slightly larger (Mr approximately 220,000) DS-PG (DS-I) can be separated from DS-II by preparative electrophoresis. Despite similarities in core size and extent of N-glycosylation between DS-I and DS-II, DS-I shows only limited ability to self-associate, and does not interact with the anti-fibroblast DS-PG antibody. DS-I glycosaminoglycan chains are also smaller (Mr approximately 18,000) than those from DS-II, similar in size to the chains borne by the DS-PG subclass of largest size (high molecular weight (HMW)-DS). HMW-DS, which predominated in cell layer extracts, runs with a Kav of 0.45 on Sepharose CL-2B and is estimated to have an Mr greater than 700,000. Reduction and alkylation of HMW-DS indicates that it forms disulfide-bonded aggregates with other matrical proteins within the cell layer. HMW-DS displayed multiple protein cores (Mr greater than 200,000) upon chondroitin ABC lyase treatment. Despite some similarity in size to the family of large, aggregating chondroitin sulfate proteoglycans and DS-PGs, immunological evidence suggests that it lacks a hyaluronic acid binding region.
...
PMID:Isolation and characterization of dermatan sulfate proteoglycans synthesized by cultured bovine aortic endothelial cells. 319 23

Dermatan sulphate proteoglycans (DSPGs) synthesized in the presence of 35SO4 were characterized in culture media of fibroblast lines obtained from skin, synovium, and gingiva. The molecular mass of DSPG varied from 95-130 kDa as estimated by SDS/polyacrylamide-gel electrophoresis. Gingival fibroblasts constantly produced larger DSPGs than skin fibroblasts. This was due to the larger dermatan sulphate (DS) chains, which also showed tissue-related heterogeneity in the distribution of 4- and 6-sulphated disaccharide units. The N-glycosylated cores (44 and 47 kDa) obtained following chondroitinase ABC treatment were of identical size in all tissues. The cores from the different tissues were also of the same size (38 kDa) when addition of the N-linked oligosaccharides was inhibited by tunicamycin or when they were removed by N-glycanase treatment. No evidence for low-molecular-mass sulphated oligosaccharides was found. All tissues contained two mRNA species (1.6 and 1.9 kb) for the DSPG core protein. These data suggest that the pattern of transferase activities involved in the construction of DS chains differs from one tissue to another. This variation may modulate the functions of DSPG in the extracellular matrix.
...
PMID:The small dermatan sulphate proteoglycans synthesized by fibroblasts derived from skin, synovium and gingiva show tissue-related heterogeneity. 322 8

Early events in the biosynthesis of alpha-glucosidase (EC 3.2.1.20) were studied in a wheat-germ cell-free translation system, using control and mutant RNA. In vitro, the primary translation product of the alpha-glucosidase mRNA is a 100 kDa protein. When canine microsomal membranes are added to the translation system, the nascent alpha-glucosidase precursor is cotranslationally transported across the microsomal membranes, yielding a 110 kDa glycosylated form. This protein has the same electrophoretic characteristics as the alpha-glucosidase precursor observed after in vivo labeling of control fibroblasts. Inhibition of glycosylation in vivo by tunicamycin or deglycosylation of the in vivo synthesized alpha-glucosidase precursor by glycopeptidase F reveals a core protein similar in molecular mass to the primary translation product. Total RNA from a patient with the adult form of glycogenosis type II is not able to direct the synthesis of normal amounts of alpha-glucosidase in vitro. Northern blot analysis of the RNA, using cloned alpha-glucosidase cDNA sequences as a probe, demonstrates that in this patient the amount of the 3.4 kb alpha-glucosidase mRNA is highly reduced. The results indicate that the synthesis or stability of the mRNA is affected.
...
PMID:Cell-free translation of human lysosomal alpha-glucosidase: evidence for reduced precursor synthesis in an adult patient with glycogenosis type II. 331 2

A large brain-specific chondroitin sulfate proteoglycan, identified with monoclonal antibody 6B4 (6B4 proteoglycan/phosphacan), was isolated from rat brain. Soluble proteoglycans in the phosphate-buffered saline extract from 20-day-old rat whole brain were fractionated by anion exchange chromatography and CsCl density gradient centrifugation. 6B4 proteoglycan was further purified by gel filtration and additional ion exchange chromatography. The molecular mass of 6B4 proteoglycan shifted from 800 to 300 x 10(3) mol. wt after chondroitinase ABC digestion. The core protein was substituted with chondroitin sulfate chains with an average molecular weight of 21,000, keratan sulfate and HNK-1 carbohydrates. Glycosidase digestion of 6B4 proteoglycan with O-glycanase, N-glycanase, endo-beta-galactosidase, or keratanase did not remove the HNK-1 epitopes. The expression of 6B4 proteoglycan was developmentally regulated in the rat cerebral cortex; appearing first at embryonic day 14, peaking at postnatal day 0, and persisting throughout adulthood at a lower level. Immunohistochemical analysis indicated that 6B4 proteoglycan was distributed along the radial glial fibers and on the migrating neurons in the embryonal rar cerebrum. The radial glial fibers were stained intensely all along their length, but the neurons in the cortical plate were not stained in contrast to the moderate staining of the migrating neurons in the intermediate zone and the subplate. From postnatal day 5 to postnatal day 20, 6B4 proteoglycan was present throughout the cortex. After postnatal day 30, staining of the neuropil was weakened, and the expression of 6B4 proteoglycan was restricted around subsets of neurons. The positive neurons were mostly non-pyramidal cells (> 95%) and were relatively concentrated in layers IV and VI of the primary somatosensory cortex. Immunohistochemical analysis of the dissociated cortical neurons indicated that 6B4 proteoglycan was distributed on the cell bodies and neurites. 6B4 proteoglycan strikingly promoted neurite extension of cortical neurons from embryonic day-16 rat embryos when coated on coverslips as a substrate. 6B4 proteoglycan is a brain-specific chondroitin sulfate proteoglycan which carries keratan sulfate and HNK-1 carbohydrates. The spatiotemporal expression profile and effects on the dissociated cerebral neurons suggest that 6B4 proteoglycan plays important roles in the migration and differentiation of neurons in the immature cortex, and also in the maintenance of subsets of neurons in the mature cortex.
...
PMID:Purification, characterization and developmental expression of a brain-specific chondroitin sulfate proteoglycan, 6B4 proteoglycan/phosphacan. 747 3

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.
...
PMID:Immunological and biochemical characterization of biglycan-like haemopoietic factor. 754 45

The mechanisms by which a stimulatory monoclonal antibody (mAb), called mAb F11, induces granular secretion and aggregation in human platelets have been characterized. Fab fragments of mAb F11, as well as an mAb directed against the platelet Fc gamma RII receptor (mAb IV.3) were found to inhibit mAb F11-induced platelet secretion and aggregation, indicating that the mAb F11 IgG molecule interacts with the Fc gamma RII receptor through its Fc domain and with its own antigen through its Fab domain. The mAb F11 recognized two platelet proteins of 32 and 35 kDa on the platelet membrane surface, as identified by Western blot analysis. We purified both proteins from human platelet membranes using DEAE-Sepharose chromatography followed by mAb F11 affinity chromatography. When added to platelet-rich plasma, the purified proteins dose-dependently inhibited mAb F11-induced platelet aggregation. The purified protein preparation also competitively inhibited the binding of 125I-labelled mAb F11 to intact platelets. The N-terminal 26 amino acid sequences of both the 32 and 35 kDa proteins were identical and contained a single unblocked serine in the N-terminal position. When digested with N-glycanase, the 32 and 35 kDa proteins were converted into a single approximately 29 kDa protein, indicating that these two proteins are derived from the same core protein but differ in their degree of glycosylation. Internal amino acid sequence analysis of the F11 antigen provided information concerning 68 amino acids and suggested two consensus phosphorylation sites for protein kinase C (PKC). The phosphorylation by PKC of the isolated F11 antigen was observed following stimulation by phorbol 12-myristate 13-acetate. Databank analysis of the N-terminal and internal amino acid sequences of the F11 antigen indicated that the N-terminal sequence exhibited the highest degree of similarity to the variable region of the alpha-chain of human T-cell receptors (TCR). In contrast, the F11 internal sequences did not exhibit any similarity to the TCR. Our results demonstrate that the F11 antigen is a novel platelet membrane surface glycoprotein which becomes cross-linked with the Fc gamma RII receptor when platelets are activated by the stimulatory mAb F11. These mechanisms may be relevant to the production of immune thrombocytopenia by platelet-activating antibodies.
...
PMID:Mechanisms of platelet activation by a stimulatory antibody: cross-linking of a novel platelet receptor for monoclonal antibody F11 with the Fc gamma RII receptor. 764 39

gp57/42 is a membrane glycoprotein localized in the trans-Golgi, flagellar pocket region of the cell surface, endosomes and lysosomes of bloodstream forms of Trypanosoma brucei rhodesiense. Pulse-chase immunoprecipitation experiments revealed that gp57/42 acquires a unique N-linked oligosaccharide recognized by the CB1 monoclonal antibody 20-30 minutes after protein synthesis, probably in the trans-Golgi. We refer to gp57/42 molecules that carry the CB1 epitope as CB1-gp. Pulse labeled CB1-gp contained only one core protein, p57, when chase times were 30 minutes or less. As time of chase increased from 30 to 60 minutes, a new polypeptide, p42, appeared in N-glycanase-treated CB1 immunoprecipitates. Since p57 and p42 share 10 of 13 methionyl peptides, we conclude that p42 is a fragment of p57. Cleavage of p57 to p42 was not inhibited when cells were chased in two thiol protease inhibitors or in 3,4-diisocoumarin, but was inhibited by leupeptin. Cell surface biotinylation was used to determine if newly synthesized CB1-gp was transported from the Golgi to the surface. When cells were pulse labeled and chased for 30 minutes, as much as 40% of the radiolabeled CB1-gp could be biotinylated on the cell surface. The amount of CB1-gp that could be biotinylated decreased when chases were extended from 30 to 60 minutes, suggesting that pulse labeled CB1-gp left the surface. In contrast, pulse labeled variant surface glycoprotein molecules continued to accumulate on the surface where they could be biotinylated between 30 and 60 minutes of chase. Biotinylated CB1-gp derived from cells chased for 30 minutes contained p57 but no p42. However, when labeled cells were biotinylated after a 30 minute chase and then incubated another 30 minutes at 37 degrees C, the biotinylated CB1-gp contained both p57 and p42. The p57 in biotinylated CB1-gp was not cleaved to p42 if the additional incubation was done at 4 or 12 degrees C. This suggests that transport to a compartment where processing occurs and/or the processing enzymes are inhibited by low temperature. When surface biotinylation was done after a 60 minute chase, p42 was detected in biotinylated CB1-gp, suggesting that CB1-gp molecules had passed through the processing compartment and then appeared on the cell surface. Thus, a major portion of the newly synthesized CB1-gp is routed from the Golgi to endocytic compartments via the cell surface. In trypanosomes this process involves a unique surface domain, the flagellar pocket.(ABSTRACT TRUNCATED AT 400 WORDS)
...
PMID:Transport of a lysosomal membrane glycoprotein from the Golgi to endosomes and lysosomes via the cell surface in African trypanosomes. 769 16

The major sulfated protein of the mouse pancreatic acinar cell, gp300, has been identified and characterized with monoclonal and polyclonal antibodies. gp300 is a glycoprotein of M(r) = 300,000 which contains approximately 40% of metabolically incorporated [35S]sulfate in the acinar cell. Sulfate on gp300 is resistant to hot 1N HCl, but sensitive to alkaline hydrolysis, demonstrating that the sulfate is carbohydrate-linked rather than tyrosine-linked. gp300 metabolically labeled with [3H]glucosamine and [35S]sulfate was chemically and enzymatically treated followed by Bio-Gel P-10 gel filtration. Both labels were resistant to treatments which degrade glycosaminoglycans. Treatment of dual-labeled gp300 with PNGase F to cleave N-linked oligosaccharides released approximately 17% of [3H] and little [35S]. Mild alkaline borohydride treatment after removal of N-linked sugar released the remainder of both labels, indicating the presence of sulfated O-linked oligosaccharides. Biosynthesis studies and PNGase F digestion indicate that the core protein is approximately 210 kDa, with apparent contributions of approximately 35 kDa N-linked sugar, and approximately 55 kDa O-linked sugar. Lectin blotting and glycosidase digestion demonstrated the presence of Gal beta(1-3)GalNAc and sialic acid alpha(2-3)Gal in O-linked oligosaccharide, and Gal beta(1-4)GlcNAc in N-linked oligosaccharide. Immunolocalization and subcellular fractionation showed that gp300 is a peripheral membrane protein localized to the lumenal face of the zymogen granule membrane. gp300 was not secreted in response to hormone stimulation of acini, so it is not a secretory product. Immunoblot analysis showed that gp300 is present in other gastrointestinal tissues and parotid glands. Localization of this nonsecreted sulfated glycoprotein to exocrine secretory granule membranes suggests that gp300 may have a role in granule biogenesis.
...
PMID:Characterization of the major sulfated protein of mouse pancreatic acinar cells: a high molecular weight peripheral membrane glycoprotein of zymogen granules. 787 32

Although several proteoglycans (PGs) have been reported in bovine periodontal ligament (PDL), the composition of PGs in PDL has been poorly characterized. In the present study, we isolated and characterized keratan sulfate-substituted PG (fibromodulin) in bovine PDL. Fibromodulin was purified from 4 M guanidine hydrochloride (GdmCl) extracts of bovine PDL tissues using DEAE Sephacel ion-exchange chromatography and preparative electrophoresis. Fibromodulin appeared as a single polydisperse band with an apparent molecular weight (MW) of 80,000 (80 kDa) on SDS-PAGE. Digestion of fibromodulin with keratanase or neuraminidase reduced the apparent molecular size, and N-glycanase treatment produced core protein bands of around 40 kDa. Fibromodulin reacted with keratan sulfate monoclonal antibody (5D4) and fibromodulin polyclonal antibodies (alpha-FM). The keratanase-digested fibromodulin reacted with alpha-FM, but not with 5D4. These data suggest that fibromodulin is one of the small PGs in the PDL-matrix and may fulfill construction and maintenance functions in this tissue.
...
PMID:Characterization of fibromodulin isolated from bovine periodontal ligament. 952 15

The biosynthesis of basement membrane heparan sulfate proteoglycan (HSPG), known as perlecan, in ACC3 cells established from a adenoid cystic carcinoma of the human salivary gland was studied using metabolic labeling and immunoprecipitation with discriminative antibodies specific for HSPG core protein. Treatment of immunoprecipitated HSPG with HNO2, heparitinase, and chondroitinase ABC revealed that ACC3 cells synthesized HSPG molecules composed of 470-kDa core protein and heparan sulfate but not of chondroitin sulfate. The core protein was shown to contain complex type N-linked oligosaccharides by digestion with N-glycanase and endoglycosidase H. Pulse-chase experiments showed that the mature form of HSPG was formed in the cells in 30 min and released into the medium thereafter. Degradation of HSPG was also found in the chase period of 3 h. In time course experiments, HSPG was found to be synthesized maximally at day 4 after plating, deposited in the cell layer maximally at day 6, and secreted maximally at day 8. This was also confirmed by immunofluorescence, Northern blotting, and in-situ hybridization. The results indicate that ACC3 cells synthesize, secrete and degrade basement membrane type HSPG, which is analogous to those produced by other cell types, and that the biosynthesis and secretion of HSPG in ACC3 cells are strictly regulated by the cell growth, that may be reflected in the characteristic histology of adenoid cystic carcinomas.
...
PMID:Basement membrane heparan sulfate proteoglycan (perlecan) synthesized by ACC3, adenoid cystic carcinoma cells of human salivary gland origin. 999 Jan 41


<< Previous 1 2 3 Next >>

---