Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cobra venom factor (CVF), the complement-activating glycoprotein in cobra venom, contains three or possibly four N-linked oligosaccharide chains per molecule and is devoid of O-linked saccharides. Analysis by lectin-affinity staining revealed the presence of complex-type oligosaccharides containing non-reducing terminal alpha-galactosyl residues and fucose residues linked to the proximal N-acetylglucosamine. Sialic acid residues could not be detected. For their structural analysis, the oligosaccharides were released by hydrazinolysis and fractionated on Bio-Gel P-4. Approximately 80% of the eluted oligosaccharides have a size equivalent of 17 +/- 2 glucose units. The major oligosaccharide representing about 45% of the total carbohydrate present in CVF was purified to homogeneity by MicroPak AX-5 HPLC and its structure was analyzed by sequential exoglycosidase digestion. The positions of the glycosidic linkages of the sugar residues were established by methylation analysis of CVF-derived glycopeptides. The data of these analyses indicated that the major oligosaccharide has a symmetrical fucosylated biantennary complex-type structure terminating with unusual alpha-galactosyl residues.
Mol Immunol 1992 Mar
PMID:Structure of the major oligosaccharide of cobra venom factor. 155 44

We have purified a novel immunoregulatory factor (BMPG: bone-marrow proteoglycan) produced by a T-cell hybridoma, with a monoclonal antibody column. Using an oligonucleotide probe corresponding to the partial amino acid sequence of BMPG, we cloned, sequenced, and expressed a cDNA for BMPG. BMPG has 222 amino acid residues with a 16 N-terminal signal sequence, so the mature form has 206 amino acid residues. BMPG was found to have unique characteristics: it has three types of sugar chains and it shows a marked homology with animal lectins including the human asialoglycoprotein receptor, chicken hepatic lectin and the homing receptor of lymphocytes.
Mol Immunol 1992 Apr
PMID:Purification and cDNA cloning of a novel factor produced by a human T-cell hybridoma: sequence homology with animal lectins. 156 1

We report the predicted sequence of four vegetative homologues (Blec1,2,3 and 4) of the pea seed lectin. This study indicates that, in contrast to the single-copy pea seed lectin (Kaminski et al., Plant Mol Biol 9:497-507, 1987), the pea vegetative lectin is transcribed by at least four members of a highly conserved multigene family whose members are only distantly related to the pea seed lectin at the primary amino-acid sequence level. For example, Blec1 shares only 38% amino-acid identity with the pea seed lectin. However, molecular homology modelling predicts that Blec1 probably forms a similar tertiary structure to the pea seed lectin.
Plant Mol Biol 1992 Mar
PMID:Predicted sequence and structure of a vegetative lectin in Pisum sativum. 158 66

Because the pulmonary alveolar space is both the site of gas exchange for respiration and a portal of entry for foreign antigen, immunologic interactions within that space must be meticulously controlled. Alveolar epithelial cells are ideally situated to play a role in immune regulation within the alveolar space. We have used A549 cells, a cell line that is derived from a human alveolar cell carcinoma and that has been used as a model for alveolar type II epithelial cells, to examine the potential role of alveolar epithelial cells in local pulmonary immune regulation. Medium conditioned by confluent monolayers of A549 cells suppressed proliferation by human peripheral blood mononuclear cells (PBMC) stimulated with lectin, anti-CD3 antibodies, calcium ionophore and phorbol ester, or in a mixed leukocyte reaction. PBMC that had been incubated in and then removed from A549-conditioned medium went on to proliferate normally. Because the suppressive effect was abrogated by heating or acidification and was not blocked by neutralizing antibody to transforming growth factor-beta 1, this effect could not be attributed to transforming growth factor-beta. The factor mediating this effect has an approximate molecular weight of 70,000 D by gel filtration chromatography. Nonalveolar, pulmonary carcinoma cell lines did not exert this immunosuppressive influence nor did the alveolar epithelial cells inhibit proliferation by the transformed, Jurkat, T-cell line. Cell cycle analysis demonstrated that PBMC exposed to A549 cell-conditioned medium failed to enter S phase after mitogen stimulation.(ABSTRACT TRUNCATED AT 250 WORDS)
Am J Respir Cell Mol Biol 1992 Jun
PMID:A factor secreted by a human pulmonary alveolar epithelial-like cell line blocks T-cell proliferation between G1 and S phase. 159 Oct 14

Hypovirulence and decreased sporulation of the plant pathogenic fungus Cryphonectria (Endothia) parasitica is caused by double-stranded (ds)RNAs. These symptoms of dsRNA infection are correlated with down-regulation of at least nine major fungal polypeptides. One of the regulated polypeptides was purified to homogeneity and antibody to it was prepared. This polypeptide (cryparin) has a -glycine-serine-repeating sequence near the amino-terminal end that is typical of structural proteins and has properties of a lectin. Antibody-staining showed that this 18.6-kDa polypeptide is specific to aerial hyphae and fruiting bodies and that it accumulates in large amounts on hyphal cell surfaces. The dsRNA affects accumulation of this protein, both in the fugal hyphae and in the growth medium. Cryparin is similar in physical properties to those of the putative phytotoxin cerato-ulmin produced by the Dutch elm disease fungus. Toxicity of cryparin is not detectable, but the striking similarities between the physical properties and locations of accumulation of cryparin and cerato-ulmin in fungal fruiting structures suggest either conservation of structure or convergent evolution in function of these two proteins.
Mol Plant Microbe Interact
PMID:Effect of a virus on accumulation of a tissue-specific cell-surface protein of the fungus Cryphonectria (Endothia) parasitica. 160 Feb 37

Lec23 Chinese hamster ovary (CHO) cells have been shown to possess a unique lectin resistance phenotype and genotype compared with previously isolated CHO glycosylation mutants (Stanley, P., Sallustio, S., Krag, S. S., and Dunn, B. (1990) Somatic Cell Mol. Genet. 16, 211-223). In this paper, a biochemical basis for the lec23 mutation is identified. The carbohydrates associated with the G glycoprotein of vesicular stomatitis virus (VSV) grown in Lec23 cells (Lec23/VSV) were found to possess predominantly oligomannosyl carbohydrates that bound strongly to concanavalin A-Sepharose, eluted 3 sugar eq beyond a Man9GlcNAc marker oligosaccharide on ion suppression high pressure liquid chromatography, and were susceptible to digestion with jack bean alpha-mannosidase. Monosaccharide analyses revealed that the oligomannosyl carbohydrates contained glucose, indicating a defect in alpha-glucosidase activity. This was confirmed by further structural characterization of the Lec23/VSV oligomannosyl carbohydrates using purified rat mammary gland alpha-glucosidase I, jack bean alpha-mannosidase, and 1H NMR spectroscopy at 500 MHz. [3H]Glucose-labeled Glc3Man9GlcNAc was prepared from CHO/VSV labeled with [3H]galactose in the presence of the processing inhibitors castanospermine and deoxymannojirimycin. Subsequently, [3H]Glc2Man9GlcNAc was prepared by purified alpha-glucosidase I digestion of [3H]Glc3Man9GlcNAc. When these oligosaccharides were used as alpha-glucosidase substrates it was revealed that Lec23 cells are specifically defective in alpha-glucosidase I, a deficiency not previously identified among mammalian cell glycosylation mutants.
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PMID:A novel glycosylation phenotype expressed by Lec23, a Chinese hamster ovary mutant deficient in alpha-glucosidase I. 166 Apr 60

The subcommissural organ (SCO) is a brain gland whose secretory material is released into the cerebrospinal fluid where it condenses into a thread-like structure known as Reissner's fiber (RF). This fiber extends along the aqueduct, fourth ventricle and central canal of the spinal cord. The present investigation was designed to identify and partially characterize the secretory products of the bovine SCO in their intracellular location and after they have been released and packed into RF form. 5,000 SCOs were dissected out under a microscope, whereas RF of 30,000 cows were collected by perfusing the central canal of the spinal cord with artificial cerebrospinal fluid. Extracts of SCO and RF were used for (i) raising polyclonal antibodies; (ii) immunoblotting; (iii) lectin binding on electrotransfers: concanavalin A (affinity = mannose, glucose) and Limax flavus agglutinin (affinity = sialic acid); (iv) immunoaffinity chromatography; (v) preparative SDS-PAGE and raising of polyclonal antibodies against each of the secretory glycoproteins identified in the immunoblots. All antibodies and the two lectins were also applied to tissue sections of the SCO and RF of several species. The immunocytochemical study of the bovine SCO using an anti-RF serum showed that the secretory material present in the rough endoplasmic reticulum (RER), secretory granules and in RF is strongly immunoreactive. Con A binding sites were only found in the endoplasmic reticulum, whereas Limax flavus agglutinin revealed secretory granules and RF, only. In the blots the immunostaining was used to identify secretory polypeptides. The glycosylated nature of the latter was established by their affinity for Con A and/or Limax flavus agglutinin. Furthermore, this latter lectin allowed us to distinguish whether the intracellular source of a secretory glycoprotein is from a pre-Golgi (RER) or a post-Golgi (secretory granules) compartment. Four glycoproteins were identified in the SCO with apparent molecular weights of 540, 450, 320 and 190 kDa. The three former were also purified by immunoaffinity chromatography. The 540 and 320 kDa forms are present in the SCO but missing in RF, have affinity for Con A, but not for LFA. It is suggested that these two compounds correspond to two precursor forms. The 450 and 190 kDa glycoproteins are present in both, the SCO and RF, and have affinity for Con A and Limax flavus agglutinin. These most likely correspond to processed forms. The presence of more than one precursor was further substantiated by immunocytochemical findings using antisera against the 540, 450 and 320 kDa forms.(ABSTRACT TRUNCATED AT 400 WORDS)
Brain Res Mol Brain Res 1991 Oct
PMID:Identification and partial characterization of the secretory glycoproteins of the bovine subcommissural organ-Reissner's fiber complex. Evidence for the existence of two precursor forms. 166 20

A high affinity binding site for [3H]dihydrotetrabenazine is thought to be present on the monoamine transport protein from chromaffin granules. We describe a procedure for purification of this binding activity from frozen bovine adrenal tissue, and we partially characterize the purified preparation. Binding activity solubilized with sodium cholate and soybean lecithin was fractionated on wheat germ lectin-Sepharose, phenyl-Sepharose, Mono Q, and hydroxylapatite. Denaturing electrophoresis of the purified binding activity, followed by silver staining, revealed a single broad band centered at an apparent molecular weight of 85,000. This preparation bound [3H]dihydrotetrabenazine with an apparent dissociation constant of 2.7 nM and had a site density of 10 nmol/mg. Treatment of the purified protein with neuraminidase reduced the apparent molecular weight by 9000, indicating the presence of terminal sialic acids on the oligosaccharide portion of this molecule.
Mol Pharmacol 1991 Dec
PMID:Purification of a [3H]dihydrotetrabenazine-binding protein from bovine adrenal medulla. 166 39

Six granular cell tumors (GCT) of the neurohypophysis were studied by immunohistochemical techniques. They were all labeled by peanut lectin (Arachis hypogaea) and three showed reactivity for S-100 protein. Unlike extracranial GCT, neuron specific enolase (NSE), myelin basic protein (MBP) and vimentin were not detected in the tumor cells. Glial fibrillary acidic protein (GFAP), keratin and desmin were also not observed. On the other hand, some showed reactivity for alpha-1-antitrypsin (AAT), alpha-1-antichymotrypsin (AAC) and cathepsin B. These results suggest that neurohypophysial GCT have some features different from extracranial GCT and that they may not be derived from Schwann cells.
Virchows Arch B Cell Pathol Incl Mol Pathol 1991
PMID:Immunohistochemical study of granular cell tumors of the neurohypophysis. 168 58

The present study was designed to shed light on the extraordinary histochemical properties of the chromophobe cell renal carcinoma detected by Hale's colloidal iron reaction. Special emphasis was laid on the lectin histochemical analysis of cytoplasmic glycoconjugates. Binding of peanut agglutinin (PNA) and Erythrina cristagalli agglutinin (ECA) after enzymatic release of sialic acid and direct binding of Dolichos biflorus agglutinin (DBA) correlates well with the expression of binding sites for Sambucus nigra agglutinin (SNA) and Maackia amurensis agglutinin (MAA) revealing abundant sialylated carbohydrate moieties within the cytoplasm. This characteristic binding pattern differs considerably from the faint staining observed in the majority of other renal carcinomas, thus confirming that the chromophobe cell renal carcinoma is a distinct entity. However, the lectin binding pattern of renal oncocytoma obviously resembles that of chromophobe carcinoma indicating a close relationship between these renal tumors. Detailed analysis of adjacent renal parenchyma revealed a lectin binding pattern quite similar to that described in the chromophobe carcinomas exclusively in the intercalated cells lining the collecting duct. This finding suggests that the chromophobe cell renal carcinoma originates from the collecting duct epithelium. The detection of small complexes consisting of altered epithelia which display the morphological characteristics of chromophobe carcinoma and the histochemical properties of intercalated cells probably indicates the emergence of preneoplastic lesions preceding the development of chromophobe carcinoma. Even though further studies are clearly needed to elucidate the physiological role of the cellular glycoconjugates detected, the present results already provide valuable insight into the histogenesis and pathogenesis of the chromophobe cell renal carcinoma.
Virchows Arch B Cell Pathol Incl Mol Pathol 1991
PMID:Sialylated glycoconjugates in chromophobe cell renal carcinoma compared with other renal cell tumors. Indication of its development from the collecting duct epithelium. 168 20


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