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PubMed2005

Health behaviour-patterns among paediatric nurses, employed in medical institutions of Greater Poland.

UNLABELLED: In the organised approach to health, a vital part is played by health education. Its main purpose is to transform populational attitudes to health and develop the sense of responsibility for it. Children constitute a particularly important populational segment in this respect. PURPOSE: The aims of this study were to establish pro-health behaviour-patterns among paediatric nurses. MATERIAL AND METHODS: Ninety-one randomly selected nurses, employed in the Greater Poland's medical institutions were queried, through a specially designed questionnaire, on their nutritional habits, physical activity, and frequency of consulting their physician. A Microsoft Excel spread sheet was employed in performing statistical calculations, making use of such functions as sum, per cent and arithmetic mean. RESULTS: Almost all subjects eat irregularly. The majority of them have two meals a day, omitting breakfasts. The proportion of ingredients containing fibre in their diet is insufficient, whereas monosaccharides are consumed excessively. The physical activity is about adequate; taking strolls are the preferred form. The respondents tend to overlook the first, disturbing disease symptoms, and rarely consult with their physician. CONCLUSIONS: (1) The life-style of paediatric nurses is not conducive to maintaining health, despite declaring the latter as the overriding life's value. (2) Chief aberrations in their health behaviour concern: irregular meals, consuming the excessive amount of monosaccharides, and preferring the passive forms of leisure. (3) In nurses' educational curriculum the role of health promotion in human life should be re-assessed, while the importance of health education in their future work should be emphasised.

Health Behavior↗
PubMed1992

Human retinal pigment epithelial cells cultured in hyperglycemic media accumulate increased amounts of glycosaminoglycan precursors.

Confluent human retinal pigmented epithelial cells were cultured on microcarrier beads in the presence of 5.6 or 26 mmol/l glucose with or without the aldose-reductase inhibitor Sorbinil (200 microM) for 2 wk. At the end of the incubation period, perchloric acid extracts were prepared and analyzed by 31P nuclear magnetic resonance spectroscopy. As assessed by this method, the phosphorylated metabolites of cells incubated with 5.6 or 26 mmol/l glucose differed significantly in the concentrations of a number of uridine diphosphate (UDP)-conjugated monosaccharides, which were elevated two- to threefold in cells incubated in 26 mmol/l glucose over control samples. The affected metabolites were identified (through a series of spiking experiments) to be UDP-N-acetylglucosamine, UDP-N-acetylgalactosamine, and UDP-glucuronic acid. Coincubation of the cells with Sorbinil 200 microM in the presence of 26 mmol/l glucose had no effect on this accumulation. Under normal circumstances, these molecules selectively and sequentially are incorporated into the polysaccharide chains of glycosaminoglycans (GAGs), whose presence and distribution in the basement membranes is affected adversely by diabetes mellitus. These data suggest that the availability of the monosaccharide precursor is not the rate-limiting step for GAG synthesis in the presence of pathologic glucose concentrations. Thus, the lost GAG content in the basement membranes of diabetic patients may be caused by changes elsewhere in the biosynthesis and/or catabolism of the polysaccharide-linked protein molecules.

Aldehyde Reductase↗
PubMed2006

[Study on the mustard of polysaccharides].

The objective of this study is to isolate and purify the polysaccharides fractions from mustard and to determine the constituent characters. Hot water extracting and ethanol precipitating method were employed to isolate polysaccharides. After the removal of protein by Sevag method, the purified mustard polysaccharides were dried by frozen drier. The amount of total carbohydrates of mustard polysaccharides was measured with phenol-sulfuric acid method. IR spectrometry, UV-spectrophotometer, and automatic spectropolarimeter were used to determine the characteristic absorption and optical rotation of the polysaccharides, respectively. Size exclusion chromatography with laser light scattering technology was employed to measure the molecular masses. The monosaccharides contained in the mustard polysaccharides were analysed by HPLC. The amount of total carbohydrates in mustard polysaccharides is 98.96%. The molecular weight distribution was 1.42 x 10(4)-2.55 x 10(6), and eighty percent was distributed in 2.1 x 10(5). The monosaccharide constituent of mustard polysaccharides were glucose, fructose, arabinose, galactose and xylose, and their molar proportions are 21.4 : 12.89 : 5.6 : 4.1 : 2.5, respectively.

Molecular Weight↗
PubMed2006

[Extraction, isolation and structure identification of polysaccharide in root of Salvia miltiorrhiza].

OBJECTIVE: To study the polysaccharide of Salvia miltiorrhiza. METHOD: The root was extracted by water and purified preliminarily by alcohol precipitation. The obtained crude polysaccharide purified by ion exchange resin DEAE-Sepharose Fast Flow then bleached with H2O2 and dialysed. Two portions of light yellow powder were obtained through lyophilization and named as SMP 1, SMP 0.5. On the basis of 13C-NMR, DEPT, IR spectra, monosaccharide composite analysis and part monosaccharide composite analysis, their structures were identified. RESULT: The molecular weight of SMP 1, SMP 0.5 was estimated to be 1.39 x 10(6), 4.03 x 10(5), respectively, and the structure of SMP 1 was mainly alpha-(1-->6) D-Glc linked a few alpha-(1-->2) D-Glc, SMP 0.5 was mainly a alpha-(1-->6) D-Glucosan. CONCLUSION: SMP 1 and SMP0.5 were neutral homosaccharides that extracted from S. miltiorrhiza for the first time.

Molecular Weight↗
PubMed1990

Effect of low molecular weight heparin preparations on the inhibition of thrombin by heparin cofactor II.

1. Heparin molecules approximately 24 to 30 residues in length are required to catalyze the thrombin-HC II reaction. The requirement for heparin molecules of this length is consistent with a model for catalysis in which heparin binds HC II and thrombin simultaneously to form a ternary complex in a manner similar to that proposed for the thrombin-AT III reaction. Smaller molecules (18 or more monosaccharide units in length) are required to catalyze the thrombin-AT III reaction. 2. The specific AT III-binding pentasaccharide containing 3-O-sulfated glucosamine is not required for activity with HC II. 3. Some low molecular weight heparin preparations have significant activity with HC II (approximately 10 to 20% that of standard heparin). This is probably related to the presence of species with molecular weights greater than 6000 to 7500 (24 to 30 monosaccharide units) in these preparations.

Antithrombin III↗
PubMed1991

Interactions of asparagine-linked carbohydrates with concanavalin A. Nuclear magnetic relaxation dispersion and circular dichroism studies.

By using near-UV circular dichroism (CD) and solvent proton nuclear magnetic relaxation dispersion measurements, three different conformational states have been detected in Ca(2+)-Mn(2+)-concanavalin A upon binding a variety of asparagine-linked carbohydrates. Two of these transitions have been described previously, one for the binding of monosaccharides such as methyl alpha-D-mannopyranoside and oligosaccharides with terminal alpha-Glc or alpha-Man residues, and the second for the binding of oligomannose and complex type carbohydrates (Brewer, C. F., and Bhattacharyya, L. (1986) J. Biol. Chem. 261, 7306-7310). The third transition occurs upon binding a bisected biantennary complex type carbohydrate with terminal GlcNAc residues. Temperature-dependent nuclear magnetic relaxation dispersion and CD measurements have identified regions of the protein near the two metal ion binding sites that are associated with the conformation changes, and Tyr-12, which is part of the monosaccharide binding site, as responsible for the CD changes. The results support our previous conclusions that the rotamer conformation of the (alpha 1,6) arm of bisected complex type oligosaccharides binds to concanavalin A with dihedral angle omega = -60 degrees whereas nonbisected complex type oligosaccharides bind with omega = 180 degrees (Bhattacharyya, L., Haraldsson, M., and Brewer, C. F. (1987) J. Biol. Chem. 262, 1294-1299). The present findings also explain the effects of increasing chain length of bisected complex type carbohydrates on their interactions with the lectin.

Asparagine↗
PubMed1990

Structure of the lipophosphoglycan from Leishmania major.

The major cell surface glycoconjugate of the parasitic protozoan Leishmania major is a heterogeneous lipophosphoglycan. It has a tripartite structure, consisting of a phosphoglycan (Mr 5,000-40,000), a variably phosphorylated hexasaccharide glycan core, and a lysoalkylphosphatidylinositol (lysoalkyl-PI) lipid anchor. The structures of the phosphoglycan and the hexasaccharide core were determined by monosaccharide analysis, methylation analysis, fast atom bombardment-mass spectrometry, one- and two-dimensional 500-MHz (correlated spectroscopy (COSY), homonuclear Hartmann-Hahn spectroscopy (HOHAHA] 1H NMR spectroscopy, and exoglycosidase digestions. The phosphoglycan consists of eight types of phosphorylated oligosaccharide repeats which have the general structure, [formula: see text] where R = H, Galp(beta 1-3), Galp(beta 1-3)Galp(beta 1-3), Arap(alpha 1-2)Galp(beta 1-3), Glcp(beta 1-3)Galp(beta 1-3), Galp(beta 1-3)Galp(beta 1-3)Galp(beta 1-3), Arap(alpha 1-2)Galp(beta 1-3)Galp(beta 1-3), or Arap(alpha 1-2)Galp(beta 1-3)Galp(beta 1-3)Galp(beta 1-3)Galp(beta 1-3), and where all the monosaccharides, including arabinose, are in the D-configuration. The average number of repeat units/molecule (n) is 27. Data are presented which suggest that the nonreducing terminus of the phosphoglycan is capped exclusively with the neutral disaccharide Manp(alpha 1-2)Manp alpha 1-. The structure of the glycan core was determined to be, [formula: see text] where approximately 60% of the mannose residues distal to the glucosamine are phosphorylated and where the inositol is part of the lysoalkyl-PI lipid moiety containing predominantly 24:0 and 26:0 alkyl chains. The unusual galactofuranose residue is in the beta-configuration, correcting a previous report where this residue was identified as alpha Galf. Although most of the phosphorylated repeat units are attached to the terminal galactose 6-phosphate of the core to form a linear lipophosphoglycan (LPG) molecule, some of the mannose 6-phosphate residues may also be substituted to form a Y-shaped molecule. The L. major LPG is more complex than the previously characterized LPG from Leishmania donovani, although both LPGs have the same repeating backbone structure and glycolipid anchor. Finally we show that the LPG anchor is structurally related to the major glycolipid species of L. major, indicating that some of these glycolipids may have a function as precursors to LPG.

Animals↗
PubMed1990

Differential recognition of core and terminal portions of oligosaccharide ligands by carbohydrate-recognition domains of two mannose-binding proteins.

Two different mannose-binding proteins (MBP-A and MBP-C), which show 56% sequence identity, are present in rat serum and liver. It has previously been shown that MBP-A binds to a range of monosaccharide-bovine serum albumin conjugates, and that, among oligosaccharide ligands tested, preferential binding is to terminal nonreducing N-acetylglucosamine residues of complex type N-linked oligosaccharides. In order to compare the binding specificity of MBP-C, an expression system has been developed for production of a fragment of this protein which contains the COOH-terminal carbohydrate-recognition domain. After radioiodination, the domain has been used to probe natural glycoproteins, neoglycoproteins, and neoglycolipids. Like MBP-A, MBP-C binds several different monosaccharides conjugated to bovine serum albumin, including mannose, fucose, and N-acetylglucosamine, although binding to the last of these is relatively weaker than observed for MBP-A. The results of binding to natural glycoproteins and to neoglycolipids containing oligosaccharides derived from these proteins are most compatible with the interpretation that MBP-C interacts primarily with the trimannosyl core of complex N-linked oligosaccharides, with additional ligands being terminal fucose and perhaps also peripheral mannose residues of high mannose type oligosaccharides. This binding specificity is thus quite distinct from that of MBP-A. The presence of multiple MBPs with distinct binding specificities in preparations derived from serum and liver explains conflicting conclusions which have been reached about carbohydrate recognition by these proteins.

Amino Acid Sequence↗
PubMed1990

Chemical change involved in the oxidative reductive depolymerization of hyaluronic acid.

The oxidative reductive depolymerization (ORD) of hyaluronate has been investigated. A solution of hyaluronate (Mr 4.07 x 10(5] in phosphate buffer (pH 7.2) was incubated in the presence of Fe2+ for 24 h at 37 degrees C under an oxygen atmosphere to yield depolymerized hyaluronate (ORD fragments; an average Mr of 2,600). The ORD fragments contain 21 and 24% less hexosamine and uronic acid, respectively, but no olefinic linkage. They were exhaustively digested with chondroitinase AC-II. The resulting oligosaccharides and monosaccharides were separated by gel filtration and ion-exchange chromatography, and their structures were determined by proton and carbon-13 NMR, fast atom bombardment mass spectrometry, and chromatographic techniques combined with chemical modifications. The following structures derived from the reducing ends of the ORD fragments were identified: 4,5-unsaturated GlcA(beta 1----3)-N-acetyl-D-glucosaminic acid (where GlcA- represents glucuronosyl-) (21%), 4,5-unsaturated GlcA(beta 1----3)GlcNAc(beta 1----3)-D-arabo-pentauronic acid (24%), and N-acetyl-D-glucosamine (51%). The following structures derived from the nonreducing ends were identified: L-threo-tetro-dialdosyl-(1----3)GlcNAc (a tentative structure, 8%), N-acetylhyalobiuronic acid (20%), and N-acetyl-D-glucosamine (45%). The results indicate that the ORD reaction of hyaluronate proceeds essentially by random destruction of unit monosaccharides due to oxygen-derived free radicals, followed by secondary hydrolytic cleavage of the resulting unstable glycosidic substituents.

Acetylglucosamine↗
PubMed1985

Fucose-activated killer (FAK) cells: anomalous killers with augmented cytotoxic activity.

The effects of monosaccharides on various lymphocyte functions have provided useful probes for the study of cell-cell interactions. In this report, we show that a monosaccharide, alpha-L-fucose, significantly enhances the cytolytic capacity of MLC-induced or preincubated effector cells. The increase in activity was seen against cytotoxic T lymphocyte (CTL) targets (:relevant PHA blasts), natural killer cell (NK) targets (:K562), and natural cytotoxic cell (NC) targets (:MA-160). In addition, traditionally NK-insensitive targets (Raji cells, irrelevant and autologous PHA blasts) were lysed after preincubation of effector cells with fucose. Conversely, ADCC activity was not significantly increased with fucose induction. The addition of fucose directly to assay cultures did not enhance NK or CTL activity, whereas other sugars, such as alpha-methyl-D-mannoside and D-fructose, were inhibitory. The proportion of target-binding cells was not affected by preincubation with fucose, but the percentage of lytic conjugates was doubled. Significant augmentation of NK activity could be observed within 24 hr of incubation with alpha-L-fucose. Conversely, when fucose was added more than 24 hr after initiation of the culture, the increase in cytolytic activity was not observed. Parallel to the increase in cytolytic activity, after preincubation with alpha-L-fucose, an increase in the expression of a newly defined human NC cell marker, HNC-1A3, was observed. The HNC-1A3+ cells were not the major subpopulation responsible for fucose-induced activity, as ascertained by the use of positively sorted cells. The populations expressing antigens defined by the antibodies OKT8 and Leu-7 showed no quantitative change. The treatment of cells with OKM1 and complement (C) before culture eliminated fucose-enhanced killing, whereas similar treatment with OKT8 and C had no significant effect. The induction of fucose-activated killers (FAK) does not result in higher concentrations of interferon (IFN) in culture supernatants, in contrast to poly I:C, which induced both higher cytolytic activity and high titers of IFN. In addition, the induction of FAK was not sensitive to 100 ng/ml of cyclosporin A, suggesting that IL 2 did not play a major role in fucose activation of killing. These results provide strong evidence that alpha-L-fucose is capable of augmenting nonspecific activity by acting on OKM1+ precursors of cytotoxic cells and influencing a postbinding event.

Cytotoxicity Tests, Immunologic↗
PubMed1987

[Antigenic bacterial polysaccharides. 23. The structure of the O-specific polysaccharide chain of Salmonella arizonae 059 lipopolysaccharide].

The O-specific polysaccharide of Salmonella arizonae O59 (Arizona 19) is composed of D-galactose, N-acetyl-D-glucosamine, and N-acetyl-L-fucosamine (FucNAc, 2-acetamido-2,6-dideoxy-L-galactose) in the ratio 1:1:1. The computerized calculation of the 13C NMR spectrum of the polysaccharide, based on the monosaccharide composition, spectra of the free monosaccharides and glycosydation effects, together with the chemical analysis (methylation and Smith degradation) showed that the polysaccharide is built up of trisaccharide repeating units of the following structure: ----3)-alpha-L-FucNAcp(1----3)-beta-D-GlcNAcp-(1----2)-beta- D-Galp-1(----. The molecular basis of serological interrelations between S. arizonae O59 and Pseudomonas aeruginosa O7 (Lányi) is discussed.

Antigens, Bacterial↗
PubMed1989

Importance of size, sulfation, and anticoagulant activity in the potentiation of acidic fibroblast growth factor by heparin.

Heparin was previously reported to potentiate the mitogenic activity of endothelial cell mitogens in a crude extract of bovine hypothalami (Thornton, S. C., Mueller, S. N., and Levine, E. M. (1983) Science 222, 623-625). We and others (Gospodarowicz, D., and Cheng, J. (1986) J. Cell. Physiol. 128, 475-484) have reported that the growth stimulatory effects of acidic fibroblast growth factor (aFGF) are potentiated in a similar manner. We have used these observations as the basis of an assay to characterize the importance of size, sulfation, and anticoagulant activity of heparin in mediating this effect. Partial nitrous acid depolymerization of heparin from porcine intestinal mucosa resulted in a mixture of heparin fragments, containing oligosaccharides ranging from disaccharides to polysaccharides of about 40 monosaccharides in length. This mixture was fractionated by ion exchange chromatography and gel permeation chromatography to obtain size-homogeneous oligosaccharides with different degrees of sulfation. Assay of these heparin-derived saccharides in the presence of a suboptimal concentration of aFGF revealed that a minimum chain length and a certain degree of sulfation is required in order to potentiate the action of aFGF. Low sulfate oligosaccharides (4-16 units) were unable to potentiate aFGF, whereas medium sulfate fractions of octadecasaccharides and larger were able to moderately potentiate aFGF. The potentiation of aFGF by the high sulfate fraction correlated with the saccharide size: 12 or more monosaccharide units were necessary to achieve potentiation equivalent to whole heparin, octa- and decasaccharides were mildly stimulatory, and hexasaccharides were without effect. In the absence of aFGF, intact heparin as well as all the oligosaccharides examined, inhibited the proliferation of capillary endothelial cells to approximately the same degree, between 20 and 50% inhibition. When a tetradecasaccharide was separated into a binding and a nonbinding fraction on matrix-bound antithrombin III, no difference was seen for these fractions in the endothelial cell proliferation assay. These results indicate that both size and sulfation of a heparin-derived oligosaccharide contribute to its ability to interact with aFGF and/or endothelial cells and that this interaction is independent of anticoagulant activity. In addition, our findings suggest that the inhibitory and potentiating effects of heparin on capillary endothelial cells have different structural requirements.

Animals↗
PubMed1986

Effect of diabetes and adrenocortical state on intestinal transport capacity and (Na+ + K+)-activated adenosine triphosphatase activity.

(Na+ + K+)-activated adenosine triphosphatase activity in the mucosal homogenate of rat small intestine estimated under conditions of experimental diabetes, application of corticosteroids, adrenalectomy or inhibition of adrenocortical function suggests a general parallelism between the capacity for monosaccharide absorption and enzyme activity. Studying the kinetic parameters it has been found that the maximal velocities of monosaccharide uptake as well as of (Na+ + K+)-activated adenosine triphosphatase reaction are significantly different, whereas sugar concentrations for halfmaximal transport velocities and enzyme-substrate affinity constants remain unaltered. From studies with purified brush borders and basolateral plasma membranes it has been shown that the activity changes were caused exclusively by that part of (Na+ + K+)-activated adenosine triphosphatase which is localized in the basolateral plasma membranes. The enzyme activity in the brush border region remains unchanged. These findings support a concept of intestinal transport mechanism which suggests that the basolateral part of (Na+ + K+)-activated adenosine triphosphatase is responsible for metabolic energy supply.

Adrenal Cortex Hormones↗
PubMed1987

Analysis of bacterial exopolysaccharides.

Extracellular polysaccharides have been isolated from cultures of freshwater and marine bacteria originally isolated from material adhering to surfaces and underivatized hydrolysates have been analyzed by high-performance liquid chromatography methods. A scheme has been developed whereby the uronic acids can be identified on strong anion-exchange columns, while neutral monosaccharides can be separated and identified using aminobonded columns or cation-exchange adsorbent loaded with a heavy metal ion. The methods permit rapid and accurate comparison of polysaccharides with differing chemotype. The strains studied show a range of different chemotypes, all containing a uronic acid and several neutral monosaccharides. Some of the polysaccharides isolated from marine bacteria possessed a very high acetyl content.

Chromatography, High Pressure Liquid↗
PubMed1987

Carbohydrate abnormalities of N-linked plasma glycoproteins in liver disease.

Glycoproteins are proteins with covalently attached carbohydrate which is enzymatically added during the biosynthesis of the polypeptide. Attachment of carbohydrate to the polypeptide may involve either an N-glycosidic or an O-glycosidic bond. Most of the plasma glycoproteins have N-linked oligosaccharides attached to appropriate asparagine moieties of the peptide core. The biosynthesis of the N-linked glycoproteins proceeds through three sequential phases which include (a) dolichol-mediated oligosaccharide assembly, (b) oligosaccharide linkage to the polypeptide, and (c) oligosaccharide processing with the addition of peripheral sugars. Much of the diversity in carbohydrate structure of plasma glycoproteins results from variations in processing and addition of peripheral sugars. The terminal monosaccharide of N-linked plasma glycoproteins is usually sialic acid, a negatively charged sugar which markedly affects the physicochemical and biologic characteristics of glycoproteins. Liver disease induces alterations in both the level and structure of many plasma glycoproteins, particularly those which are synthesized by the hepatocyte. Quantitative changes in the concentration of plasma glycoproteins are relatively easy to assess due to the availability of many types of clinical assays. Furthermore, quantitation of the level of a particular glycoprotein in the plasma often provides clinically useful information pertinent to diagnosis and progression of disease. The determination of functional abnormalities of glycoproteins and the correlation of these functional changes with potential alterations in carbohydrate structure is more difficult, however, due to the need for accurate functional assays and sophisticated methods for analysis of the carbohydrate structure of the abnormal molecules, which are themselves often scarce. Liver disease-induced alterations in the oligosaccharide moieties of plasma glycoproteins involve mainly hyperglycosylation or hypoglycosylation defects. These changes can often be traced to increases or decreases in the amount of sialic acid present within the abnormal structure. Since sialic acid plays such a key role in the biology of glycoproteins, changes in the amount of this monosaccharide frequently result in marked alterations in the physicochemical and biologic behavior of the abnormal molecule. The exact mechanisms responsible for the changes in sialic acid are not entirely known, since the complete oligosaccharide structure of any of the abnormal glycoproteins of liver disease has not been determined.(ABSTRACT TRUNCATED AT 400 WORDS)

Carbohydrate Conformation↗
PubMed1986

Comparative analysis of natural killer cell and macrophage recognition of concanavalin A-resistant Chinese hamster ovary cells: role of membrane oligosaccharides.

As was previously shown, a mutation rendering Chinese hamster ovary (CHO) cells concanavalin A (Con A) resistant (Con AR) resulted in enhanced binding and susceptibility to lysis by natural killer (NK) cells. In the present study altered cell surface carbohydrate expression on the Con AR CR-7 cell line was demonstrated. This could be detected by flow cytometry with the use of fluorescein isothiocyanate-conjugated lectins Con A, wheat-germ agglutinin, and peanut agglutinin, and by a radiolabeled monoclonal antibody (49H.8) that recognizes a phenyl-P-galactose determinant. Two other independently selected Con AR CHO lines (BCR-2 and ECR-1) also exhibited increased NK cell reactivity, which suggests that a similar and, likely, a single mutation has altered the phenotype of these cells. Tunicamycin, an inhibitor of N-linked glycosylation, was able to reverse the binding to the CHO lines with the use of conditions that did not affect protein or DNA synthesis. The mutation rendering the CR-7 line Con AR and more sensitive to NK cell lysis and binding resulted in reduced killing and adhesion by activated bone marrow-derived macrophages from DBA/2J and CBA/CaJ mouse strains. Inhibition of macrophage and NK cell lysis by simple monosaccharides was demonstrated; however, macrophage killing was inhibited only by D-mannose, whereas NK cell lysis was reduced by all sugars tested. Neither macrophage nor NK cell adherence to tumor monolayers was affected by any of the monosaccharides. These results suggest that complex N-linked oligosaccharides are important for NK cell and macrophage binding and lysis.

Animals↗
PubMed1986

Comparison of the specificities of laminin, thrombospondin, and von Willebrand factor for binding to sulfated glycolipids.

The adhesive glycoproteins laminin, thrombospondin, and von Willebrand factor bind specifically and with high affinity to sulfated glycolipids. These three glycoproteins differ, however, in their sensitivity to inhibition of binding by sulfated monosaccharides and polysaccharides. Heparin strongly inhibits binding of thrombospondin but only weakly inhibits binding of laminin and von Willebrand factor. Fucoidan strongly inhibits binding of both laminin and thrombospondin but not of von Willebrand factor. Laminin shows significant specificity for inhibition by monosaccharides, whereas thrombospondin does not. Thus, specific spacial orientations of sulfate esters may be primary determinants of binding for the three proteins. Laminin, thrombospondin, and von Willebrand factor also differ in their relative binding affinities for purified sulfated glycosphingolipids. The three proteins strongly prefer terminal-sulfated lipids and bind only weakly to sulfated gangliotriaosyl ceramide with a sulfate ester on the penultimate galactose. Thrombospondin binds with highest affinity to galactosyl sulfatide but only weakly to more complex sulfatides, whereas von Willebrand factor prefers galactosyl sulfatide but binds with moderate affinity to various sulfated glycolipids. Laminin also is less selective than thrombospondin but is less sensitive for detection of low sulfatide concentrations. Galactosyl sulfatide at 1-5 pmol can be detected by staining of lipids separated on high performance TLC with 125I-thrombospondin or 125I-von Willebrand factor. 125I-von Willebrand factor was examined as a reagent for detecting sulfated glycolipids in tissue extracts. Rat kidney lipids contain 5 characterized sulfated glycolipids: galactosyl ceramide I3-sulfate, lactosyl ceramide II3-sulfate, gangliotriaosyl ceramide II3-sulfate, and bis-sulfated gangliotriaosyl and gangliotetraosyl ceramides. von Willebrand factor detects all of these lipids as well as several additional minor sulfated lipids. Complex monosulfated lipids are detected in several human tissues including kidney, erythrocytes, and platelets by this technique.

Blood Platelets↗
PubMed1987

Increased concentrations of HbAlab in hereditary fructose intolerance and galactosemia.

In patients with diabetes mellitus nonenzymatic glycosylation of hemo-globin is a result of increased blood glucose concentrations. In analogy glycosylated hemo-globin fractions were determined in 23 patients with hereditary fructose intolerance (HFI) and 8 patients with galactosemia (G) by means of hemoglobin chromatography on a column packed with Bio-Rex 70 resin. The concentrations were compared to those of 14 control patients and 43 patients with type 1 diabetes mellitus. Compared to controls, in HFI- and G-patients HbAlab was significantly increased. In contrast diabetic patients presented with a marked and significant increase of the HbAlc fraction. When purified hemoglobin was incubated with different monosaccharides respectively monosaccharide phosphates, an increase of HbAlab resulted mainly after galactose and fructose-1-phosphate. The determination of HbAlab in patients with HFI and G is considered a possible means of metabolic control.

Carbohydrate Metabolism, Inborn Errors↗