共查询到20条相似文献,搜索用时 15 毫秒
1.
G.V. Avvakumov I.V. Matveentseva L.V. Akhrem O.A. Strelchyonok A.A. Akhrem 《Biochimica et Biophysica Acta (BBA)/General Subjects》1983,760(1):104-110
Sex hormone-binding globulin from human blood serum contains two biantennary N-linked oligosaccharide chains of the N-acetyllactosamine type and one O-linked oligosaccharide per one molecule of the glycoprotein. These conclusions have been based on the results of methylation analysis of the whole glycoprotein and investigation of the structures of its glycopeptides prepared using pronase digestion. 相似文献
2.
Nirupama Mohapatra William S. Lynn Sambhu N. Bhattacharyya 《Biochimica et Biophysica Acta (BBA)/General Subjects》1983,760(3):398-402
A glycoprotein with a molecular weight of 62 000 has been isolated from a tumor-cell line, A549, and purified to homogeneity by gel chromatography. The glycoprotein contained sialic acid, galactose, mannose, N-acetylglucosamine and a relatively high amount of glutamic acid and proline. The data indicated that the overall composition of this glycoprotein was different from that of the glycoprotein of Mr 62 000 isolated from lung lavage of patients with alveolar proteinosis. The glycoprotein did not react with the antiserum from lung lavage of patients with alveolar proteinosis. The glycoprotein did not react with the antiserum raised against glycoprotein of Mr 62 000 isolated from lung lavage of patients with alveolar proteinosis. 相似文献
3.
G.N. Hannan J.W. Redmond B.R. McAuslan 《Biochimica et Biophysica Acta (BBA)/General Subjects》1984,801(3):396-402
Plasma and cellular fibronectins are reported to be very similar but not identical in chemical structure. We have compared bovine plasma fibronectin with fibronectin secreted by bovine aortal endothelial cells in culture. Techniques were chosen to highlight likely structural differences, particularly in the carbohydrate moieties. Both fibronectins were wholly reactive to monospecific antiserum and behaved identically in two-dimensional gel electrophoresis. The oligosaccharide chains were identical in proportion and degree of sialylation by anion-exchange HPLC. Fractionation of the glycopeptides on immobilised lectins and serotonin showed that both fibronectins contained (i)_predominantly biantennary oligosaccharides, (ii) exclusively N-acetylneuraminic acid residues in a non-clustered array and (iii) no L-fucose residues. The overriding structural similarities support the proposal that the endothelium is a site of synthesis of plasma fibronectin in vivo. 相似文献
4.
Oleg Iourin Taj S. Mattu Nasi Mian Geoffrey Keir Bryan Winchester Raymond A. Dwek Pauline M. Rudd 《Glycoconjugate journal》1996,13(6):1031-1042
One of the biochemical characteristics of carbohydrate deficient glycoprotein syndromes is the presence of abnormal glycoforms in serum transferrin. Both glycoform heterogeneity and variable site occupancy may, in principle, lead to the generation of a range of glycoforms which contain different numbers of sialic acid residues, and therefore variable amounts of negative charge. Capillary zone electrophoresis was used to resolve the glycoforms of normal human serum transferrin and also of a set of glycoforms which were prepared by digesting the sugars on the intact glycoprotein with sialidase. The sugars on the intact glycoprotein were also modified by a series of exoglycosidase enzymes to produce a series of neutral glycoforms which were also analysed by capillary zone electrophoresis. The oligosaccharide population of human serum transferrin was analysed by a series of mixed exoglycosidase digests on the released glycan pool and quantified using a novel HPLC strategy. Transferrin was isolated from carbohydrate deficient glycoprotein syndromes type I serum and both the intact glycoforms and released sugars were resolved and quantified. The data presented here confirm the presence of a hexa-, penta- and tetra-sialoforms of human serum transferrin in both normal and carbohydrate deficient glycoprotein syndrome type I serum samples. Consistent with previous reports carbohydrate deficient glycoprotein syndrome type I transferrin also contained a di-sialoform, representing a glycoform in which one of the two N-glycosylation sites is unoccupied, and a non-glycosylated form where both remain unoccupied. This study demonstrates that capillary zone electrophoresis can be used to resolve quantitatively both sialylated and neutral complex type glycoforms, suggesting a rapid diagnostic test for the carbohydrate deficient glycoprotein syndromes group of diseases.Abbreviations CDGS
Carbohydrate Deficient Glycoprotein Syndrome
- CZE
Capillary Zone Electrophoresis
- hTf
human transferrin
- gu
HPLC glucose units
- EOF
electroosmotic flow. Nomenclature: for describing oligosaccharide structures: A(1,2,3,4) indicates the number of antennae linked to the t trimannosyl core
- G(0–4)
indicates the number of terminal galactose residues in the structure
- F
core fucose
- B
bisecting N-acetyl glucosamine (GlcNAc)
- S
sialic acid
- Gal
galactose; M
- Man
mannose 相似文献
5.
Brian Fowler 《Biochimica et Biophysica Acta (BBA)/Molecular Cell Research》1982,721(2):201-207
The ability of human skin-fibroblasts in monolayer culture to carry out transsulphuration and remethylation of homocysteine has been tested. The conversion of homocyst(e)ine to cyst(e)ine and methionine was studied in control and mutant cells by incubation for 16 h with l-[35S]homocystine. Labelled cysteic acid and methionine sulphone were found in hydrolysates of oxidized cell proteins. The quantities found were dependent on the time of incubation and were used as a measure of cyst(e)ine and methionine formation, respectively. In control cells, labelled cyst(e)ine and labelled methionine were found. In cystathionine β-synthase-deficient cell lines, labelled cyst(e)ine formation was reduced, while labelled methionine formed was similar to that of controls, indicating the role of transsulphuration in the formation of cyst(e)ine observed in control cells. In a 5,10-methylenetetrahydrofolate reductase-deficient cell line, labelled methionine formation was reduced, indicating the role of N-5-methyltetrahydrofolate-requiring methylation of homocysteine in the formation of methionine observed in control cells. 相似文献
6.
Kim L. Hossner Reinhart B. Billiar 《Biochimica et Biophysica Acta (BBA)/General Subjects》1979,585(4):543-553
Plasma kinetics and liver metabolism of iodanated human corticosteroid-binding protein have been studied in ovariectomized female rats. 125I-labeled human corticosteroid-binding globulin prepared by a modified chloramine T reaction was shown to be physically intact and biologically active. Intravenously injected 125I-labeled human corticosteroid-binding globulin was shown to give a complex clearance pattern from the plasma, with half-lives of 7.5 and 51 min. Estrogen injections had no effect on plasma clearance rate. Direct involvement of liver plasma membrane receptors for asialoglycoproteins in 125I-labeled human corticosteroid-binding globulin metabolism was demonstrated in vivo and in vitro using asialofetuin as a competitive inhibitor. 125I-labeled human asialo-corticosteroid-binding globulin was cleared from the plasma with a half-life of less than 1 min, while the simultaneous injection of 5 mg asialofetuin maintained the circulating plasma levels. Asialofetuin also slowed the clearance of intact 125I-labeled human corticosteroid-binding globulin from the plasma (). Binding of 125I-labeled human asialo-corticosteroid-binding globulin to rat liver plasma membranes in vitro was inhibited in a dose-dependent manner by asialofetuin, but not by intact human corticosteroid-binding globulin or fetuin. 125I-labeled human corticosteroid-binding globulin did not bind significantly to the membranes. It is concluded that human corticosteroid-binding globulin clearance from rat plasma is rapid and that the carbohydrate moiety of human corticosteroid-binding globulin is involved in its clearance and catabolism by the liver. 相似文献
7.
Structural investigation of the carbohydrate element of human pituitary follicle-stimulating hormone by methylation analysis
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A preparation of human follicle-stimulating hormone has been subjected to methylation analysis by using the methyl sulphinyl carbanion-dimethyl sulphoxide-methyl iodide method. The hydrolysis products of the methylated glycoprotein were reduced, acetylated, analysed by gas-phase chromatography and mass spectrometry and identified by comparison with standards. Methylation analysis demonstrated that (1) the d-galactose, mannose, fucose and 2-amino-2-deoxyglucose units exist in the pyranose forms, (2) the 2-amino-2-deoxyglucose units are N-acetylated, (3) the fucopyranose units occupy terminal non-reducing positions, (4) the d-galactopyranose units are linked in the 1- and 2-positions, (5) the mannopyranose units exist in three forms, some as terminal non-reducing residues, some as 1,6-linked residues and some as 1,3,4-linked branch points, and (6) the 2-acetamido deoxyglucopyranose units are 1,6-linked. These structural assignments are compared with other data previously obtained for the carbohydrate moieties of follicle-stimulating hormone. 相似文献
8.
Xiaobo Mao Xiaojing Ma Lei Liu Lin Niu Yanlian Yang Chen Wang 《Journal of structural biology》2009,167(3):209-215
We demonstrate in this work that scanning tunneling microscopy (STM) provides a useful approach to obtaining structural information about human islet amyloid polypeptide (hIAPP) and rat islet amyloid polypeptide (rIAPP) assembly on highly oriented pyrolytic graphite (HOPG) with sub-molecular resolution. The observed hIAPP and rIAPP lamellae consisted of parallel stripes. The STM images of hIAPPs show multiple molecular folding structures, with an average of 11 amino acid residues for the core regions. In addition, the STM images also reveal the assembly characteristics of rIAPP lamellae and may indicate a secondary structural conformation from random coil to beta-sheet-like on the graphite surface. 相似文献
9.
Kozlov G Pocanschi CL Rosenauer A Bastos-Aristizabal S Gorelik A Williams DB Gehring K 《The Journal of biological chemistry》2010,285(49):38612-38620
The calnexin cycle is a process by which glycosylated proteins are subjected to folding cycles in the endoplasmic reticulum lumen via binding to the membrane protein calnexin (CNX) or to its soluble homolog calreticulin (CRT). CNX and CRT specifically recognize monoglucosylated Glc1Man9GlcNAc2 glycans, but the structural determinants underlying this specificity are unknown. Here, we report a 1.95-Å crystal structure of the CRT lectin domain in complex with the tetrasaccharide α-Glc-(1→3)-α-Man-(1→2)-α-Man-(1→2)-Man. The tetrasaccharide binds to a long channel on CRT formed by a concave β-sheet. All four sugar moieties are engaged in the protein binding via an extensive network of hydrogen bonds and hydrophobic contacts. The structure explains the requirement for glucose at the nonreducing end of the carbohydrate; the oxygen O2 of glucose perfectly fits to a pocket formed by CRT side chains while forming direct hydrogen bonds with the carbonyl of Gly124 and the side chain of Lys111. The structure also explains a requirement for the Cys105–Cys137 disulfide bond in CRT/CNX for efficient carbohydrate binding. The Cys105–Cys137 disulfide bond is involved in intimate contacts with the third and fourth sugar moieties of the Glc1Man3 tetrasaccharide. Finally, the structure rationalizes previous mutagenesis of CRT and lays a structural groundwork for future studies of the role of CNX/CRT in diverse biological pathways. 相似文献
10.
Teiko Yamashita Jun-ichiro Murayama Hideo Utsumi Akira Hamada 《Biochimica et Biophysica Acta (BBA)/General Subjects》1985,839(1):26-31
Dog glycophorin, the major sialoglycoprotein of dog erythrocyte membranes, contains either N-acetyl- or N-glycolylneuraminic acid, depending upon the strain of dog. Glycolipids also contained the same sialic acid as those found in glycophorin when both materials are prepared from erythrocyte membranes of individual dogs. The O-glycosidic oligosaccharides were released from glycophorin, prepared from individual dogs, by alkaline borohydride treatment, and purified by gel filtration and ion-exchange chromatography. The structures of the reduced oligosaccharides were determined by methylation analysis and gas-liquid chromatography-mass spectrometry. The O-glycosidic oligoscharides identified were one tetrasaccharide - Neu5Ac(2→3)Gal)1→3)[Neu5Ac(2→6)[GalNAcol - two trisaccharides - Neu5Ac(2→3)Gal1→3)GaINAcol and Gal(1→3)[Neu5Ac(2→6)]GalNAcol. 相似文献
11.
Anna Hanuszkiewicz Paula Pittock Fiachra Humphries Hermann Moll Amanda Roa Rosales Antonio Molinaro Paul N. Moynagh Gilles A. Lajoie Miguel A. Valvano 《The Journal of biological chemistry》2014,289(27):19231-19244
Burkholderia cenocepacia is an opportunistic pathogen threatening patients with cystic fibrosis. Flagella are required for biofilm formation, as well as adhesion to and invasion of epithelial cells. Recognition of flagellin via the Toll-like receptor 5 (TLR5) contributes to exacerbate B. cenocepacia-induced lung epithelial inflammatory responses. In this study, we report that B. cenocepacia flagellin is glycosylated on at least 10 different sites with a single sugar, 4,6-dideoxy-4-(3-hydroxybutanoylamino)-d-glucose. We have identified key genes that are required for flagellin glycosylation, including a predicted glycosyltransferase gene that is linked to the flagellin biosynthesis cluster and a putative acetyltransferase gene located within the O-antigen lipopolysaccharide cluster. Another O-antigen cluster gene, rmlB, which is required for flagellin glycan and O-antigen biosynthesis, was essential for bacterial viability, uncovering a novel target against Burkholderia infections. Using glycosylated and nonglycosylated purified flagellin and a cell reporter system to assess TLR5-mediated responses, we also show that the presence of glycan in flagellin significantly impairs the inflammatory response of epithelial cells. We therefore suggest that flagellin glycosylation reduces recognition of flagellin by host TLR5, providing an evasive strategy to infecting bacteria. 相似文献
12.
Diana L. Blithe H.Fred Clark Leonard Warren 《Biochimica et Biophysica Acta (BBA)/General Subjects》1982,719(2):190-198
The carbohydrate groups of the glycoproteins of human, hamster, chick, reptile and fish cells growing in culture have been fractionated in succession according to size (Sephadex G-50), affinity for concanavalin A, charge (DEAE-Sephadex) and by thin-layer chromatography. It was found that despite the complexity of the array of separable glycopeptides in each type of cell, most of these structures seemed to be common to all of the cells. This suggests that they have existed in a relatively stable state for several hundreds of millions of years throughout the evolution of the vertebrates. 相似文献
13.
Indium(III) chloride catalyzed microwave assisted acetylation of different carbohydrates is an efficient synthesis of per-O-acetyl derivatives and provides the products in good to excellent yields. 相似文献
14.
Summary The effect of chloroquine, an inhibitor of intralysosomal catabolism, on the synthesis, transport, and degradation of cell-coat glycoproteins in absorptive cells of cultured human small-intestinal tissue was investigated by morphometrical, autoradiographical, and biochemical methods. Neither synthesis nor transport of cell-coat material was affected by the drug, but culturing of the absorptive cells in the presence of chloroquine led to a dose- and time-dependent enlargement of the dense bodies; other cell structures showed no alterations. 3H-fucose-labelled material accumulated in the dense bodies of the absorptive cells of these cultures. Since no increase of -glucuronidase and acid phosphatase activity (both lysosomal enzymes of glycoprotein nature) was found, this accumulation of radiolabelled material can be explained as a chloroquine-mediated inhibition of the degradation of cell-coat glycoproteins. These macromolecules probably enter the lysosome-like bodies by a crinophagic mechanism, i.e., fusion of these organelles with the apical vesicles and tubules involved in intracellular transport. These findings suggest that the lysosome-like bodies have a function in the regulation of cell-coat glycoprotein transport in human intestinal absorptive cells, i.e., the degradation of excess cell-coat material. 相似文献
15.
Tadao Saito Takatoshi Itoh Susumu Adachi 《Biochimica et Biophysica Acta (BBA)/General Subjects》1984,801(1):147-150
Two neutral disaccharides which comprise 74.0% of the neutral oligosaccharides other than lactose were isolated from bovine colostrum taken 6 h after parturition. The chemical structures were revealed to be galactosyl-β-1,4-N-acetylglucosamine (N-acetyllactosamine, 70.3%) and N-acetylgalactosaminyl-β-1,4-glucose (3.7%). The two carbohydrates were the newly found oligosaccharides from mammalian milk in the free forms. 7 days after parturition, they had completely disappeared from bovine milk. 相似文献
16.
Wannee Rojanapo James Allen Olson Adrian J. Lamb 《Biochimica et Biophysica Acta (BBA)/General Subjects》1980,633(3):386-399
Glycoproteins and proteins were extracted from segments or scrapings of the intestine in tube-fed, vitamin-A-deficient and control rats on the eight day after withdrawal of retinoic acid from the diet by using either 1% sodium dodecyl sulfate (SDS) or aqueous 5 mM EDTA (pH 7.4). They were then fractionated on columns of Sepharose 4B. Water-soluble peak I material contained large (Mr > 106; S20 = 11.7) glycoprotein aggregates which were rich in hexose, fucose and sialic acid. These aggregates dissociated into several non-identical glycoprotein and protein subunits upon treatment with dithiothreitol. The protein matrix was rich in threonine, valine, proline, serine, glutamate and aspartate. Peak II consisted of smaller proteins and glycoproteins, the latter with much lower carbohydrate content. Some peak II glycoproteins also dissociated into subunits in the presence of dithiothreitol. Peak III consisted mainly of a heterogenous assortment of proteins, including some glycoproteins of low carbohydrate content. Antibodies either to peak II or to peak III reacted both with peaks II and III but not with peak I.The total weight, carbohydrate composition of glycoproteins and the ratio of carbohydrate to protein in the total extract or in each of the three fractions were not significantly affected in vitamin A deficiency despite decreased incorporation of all labeled precursors. Rather, the relatively lower incorporation (approx. 0.8) of radioactive sulfate, D-glucosamine and L-fucose into total SDS-soluble duodenal glycoproteins of vitamin-A-deficient rats could be explained on the basis of a reduced prevalence of goblet cells alone. In contrast, the relative incorporation rate of L-fucose into peak I, but not into peaks II and III, ranged from 0.25 to 0.45, less than expected on the basis of fewer goblet cells alone. The incorporation of radioactive threonine into all protein fractions was reduced to 60% of normal in vitamin A deficiency. Thus, the well established observation that intestinal tissue of vitamin-A-deficient rats synthesizes high molecular weight glycoproteins poorly might be due to several interacting factors: (1) a reduced prevalence of goblet cells, (2) a lower rate of protein synthesis, (3) a lack of retinyl phosphate for the formation of mannosyl or other carbohydrate derivatives, and (4) secondary, and as yet undefined, cellular changes which preferentially reduce the rate of synthesis of high molecular weight fucose- and sialic-acid-enriched glycoproteins. 相似文献
17.
Patrick Cammarata Linda Chan Costante Ceccarini 《Biochimica et Biophysica Acta (BBA)/General Subjects》1981,674(1):128-135
The normal human fibroblast, WI-38, was labelled with radioactive mannose and its incorporation, as well as the accumulation of acidic and neutral glycopeptides on the cell surface, was followed as a function of time. The transit time of newly made Pronase-released cell surface glycopeptides from their intracellular site of synthesis to the cell surface was slower in nongrowing cells than in a rapidly growing culture. When the surface glycopeptides were separated by high-voltage paper electrophoresis into neutral and acidic species, it was observed that the cell surface material was initially enriched with neutral glycopeptides. However, with time the relative proportion of acidic species increased so that by 3 h the ratio between the acidica and neutral species approached a constant value. Our data are consistent with the hypothesis that multiple pathways for asparagine-linked glycoprotein biosynthesis are possible. 相似文献
18.
R.G. Ashcroft K.R. Thulborn J.R. Smith H.G.L. Coster W.H. Sawyer 《生物化学与生物物理学报:生物膜》1980,602(2):299-308
Dielectric measurements on lecithin/cholesterol bimolecular lipid membranes have indicated that the series of extrinsic fluorescent probe molecules, the fatty acids, cause significant perturbation to the bilayer structure at concentrations equivalent to those used in fluorescence experiments (0.1 mol%). Perturbations were observed in the capacitance and conductance of the electrically distinct substructural regions of the bilayer that were consistent with the putative location of the probe molecules. Inclusion of stearic acid decreased the thickness of the hydrocarbon region of the membrane, presumably by expanding the average surface area per unit membrane mass, and also significantly disrupted the surface regions. The attachment of the anthroyloxy moiety to position 2 of a fatty acid accentuated both these effects. Attachment at position 12 had the reverse effect by increasing the volume of the hydrocarbon region without further disturbance of the surface organisation. The 9-positioned probe had an intermediate effect. The degree of perturbation by the 2-positioned probe was dependent on the probe concentration within the range (probe:lipid) 1:1000 to 1:10 000. The technique therefore detects perturbation of structure at probe levels which are lower than those commonly used in fluorescence-labelling experiments. 相似文献
19.
Friend erythroleukemia cells display transient and permanent changes in the composition of their plasma membrane-bound glycoproteins during dimethyl sulfoxide-induced differentiation. The transient changes, as revealed by metabolic labeling with [14C]glucosamine, are most conspicuous around the time during which most cells become committed to terminal differentiation. Permanent changes are revealed by reductive tritiation after oxidation with NaIO4 or galactose oxidase. In differentiated cells one glycoprotein fraction (Mr 150 000) could not be labeled by any of these methods, although it does contain neuraminic acid. We found no evidence in support of the hypothesis that the anomalous behavior of this fraction is caused by an increased degree of O-acetylated neuraminic acid in the plasma membrane of differentiated cells. 相似文献
20.
Johannis P. Kamerling Josef Makovitzky Roland Schauer Johannes F.G. Vliegenthart Margret Wember 《Biochimica et Biophysica Acta (BBA)/General Subjects》1982,714(2):351-355
Analysis of the sialic acids obtained by mild acid hydrolysis of B lymphocytes reveals the presence of N-acetylneuraminic acid and 9-O-acetyl-N-acetylneuraminic acid. For T lymphocytes only N-acetylneuraminic acid has been demonstrated to occur. The applied methods include quantitative colorimetry, thin-layer chromatography and combined gas-liquid chromatography-mass spectrometry. 相似文献