Fetuin: Immunochemistry and quantitative estimation in serum

Bergmann, Fred H.; Levine, Lawrence; Spiro, Robert G.

doi:10.1016/0006-3002(62)90815-6

Cited by 82 publications

(22 citation statements)

References 16 publications

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“…Normal rabbit serum was used in the buffer system of our radioimmunoassay procedure instead of bovine serum albumin because the source from which commercially available albumin is purified is unknown and fetuin contamination is possible if calf sera are used as the source of albumin. A double-antibody assay system to precipitate the 125I-labelled fetuin-antibody complex was avoided because such a procedure involves the use of a secondary antibody produced in a goat or sheep, and it has been reported that sera of these animals contain proteins that cross-react with bovine fetuin (Bergmann, Levine & Spiro, 1962).…”

Section: Discussionmentioning

confidence: 99%

Distribution of bovine fetuin and albumin in plasma, allantoic and amniotic fluids during development

Lai¹,

Huang²,

Panrucker³

et al. 1981

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Summary. A radioimmunoassay for bovine fetuin was developed and its specificity and validity established. Albumin was measured by radial-immunodiffusion assay.Fetuin levels in fetal plasma increased from 10 to 15 mg/ml between 4 and 8 months of gestation; albumin levels remained higher than fetuin. Neonatal plasma fetuin levels rapidly declined during the first 14 days post partum, coincident with a marked reciprocal increase in albumin levels. In allantoic fluid fetuin and albumin concentrations reached a peak at 7 months but fetuin values were always higher. In amniotic fluid both proteins peaked at 8 months; albumin levels were similar to those in allantoic fluid but fetuin values remained consistently lower than those in allantoic fluid throughout gestation. Fetuin levels in maternal plasma declined from 0\m=.\7to 0\m=.\4 mg/ml between 1 month and term. We conclude that (1) at term there is an abrupt change from fetuin synthesis to increased albumin synthesis by the neonatal liver; (2) fetuin appears to be preferentially accumulated in the allantois whereas albumin is equally concentrated in the allantois and amnion.

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Section: Discussionmentioning

confidence: 99%

Distribution of bovine fetuin and albumin in plasma, allantoic and amniotic fluids during development

Lai¹,

Huang²,

Panrucker³

et al. 1981

Reproduction

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“…It has been noted that when animals are immunized with a glycoprotein such as fetuin, the elicited immune response is predominantly directed at the protein portion of the molecule and not at the carbohydrate moiety (8). The difficulty of raising antibodies to sugar portions of glycoproteins may be due to the obvious similarities (Fig.…”

Section: Discussionmentioning

confidence: 99%

“…glycoproteins (8). This difficulty may be due to the obvious similarity between the saccharide structures appearing in unrelated serum glycoproteins and in cell surface receptors ( Fig.…”

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confidence: 99%

Antibodies reactive with cell surface carbohydrates.

Sela

Wang

Edelman

1975

Proc. Natl. Acad. Sci. U.S.A.

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Normal and immune sera from various animal species were fractionated on columns of Sepharose covalently coupled with the glycoprotein fetuin. Elution of the material bound to fetuin yielded low but reproducible amounts of protein, ranging from 0.02 to 0.2% of the protein mass of the input sera. This material has been identified by immunoelectrophoresis in agar and by zone electrophoresis on cellulose acetate as immunoglobulin. The Ig fractions bound and agglutinated erythrocytes of various species, and also bound to cells from various mouse tissues including heart, kidney, thymus, and spleen. In all cases, the binding was inhibited by glycoproteins such as fetuin and thyroglobulin, by a glycopeptide isolated from fetuin, and by some bacterial lipopolysaccharides. When the binding of these Ig fractions to mouse splenocytes was tested in the presence of 17 saccharides, no inhibition of binding was observed except by sialic acid, D-galactose, N-acetyl-D-glucosamine, and D-mannose, all of which showed partial inhibition. Inasmuch as these four saccharides are present on the carbohydrate moiety of fetuin, the results suggest that the isolated material is a carbohydrate-specific Ig (CS-Ig) fraction of serum capable of binding to the carbohydrate portion of cell surface receptors and glycoproteins. When bound to lymphocytes, these CS-Ig molecules induced redistribution (patching and capping) of cell surface receptors. Moreover, the CS-Ig fractions from chicken and rabbit sera were weakly mitogenic for mouse splenic lymphocytes. CS-Ig fractions are useful new reagents for studying glycoproteins and the interactions and activities of cell surface carbohydrates.

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“…Human and mouse peripheral lymphocytes were agglutinated by both ACBA-1 (25 (30). The similarities of the carbohydrate moieties of the serum glycoproteins (1,31) and cell surface receptors (32,33) would be recognizable as "self" antigens.…”

Section: Resultsmentioning

confidence: 99%

Protein-sugar interactions: preparation, purification, and properties of rabbit antibodies against di-N-acetylchitobiose.

Kiéda¹,

Delmotte²,

Monsigny³

1977

Proc. Natl. Acad. Sci. U.S.A.

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Antibodies against di-N-acetylchitobiose (CB) were raised in rabbits after injection of CB-bovine serum albumin conjugates and were fractionated by columns into two classes: the first bound to a column of Sepharose covalently coupled with N-acetylglucosamine (GlcNAc); the second bound to a column coupled with CB. Active antibodies were eluted by a moderate concentration of a chaotropic agent, but not by high ionic strength buffers or acidic buffers. The active fractions were identified as IgG by ultracentrifugation and immunoelectrophoresis. These antibodies gave precipitation bands with CB-protein conjugates and this reaction could be reversed in the presence of free CB. The GlcNAc-bound fraction quantitatively quenched the fluorescence of 04-methylumbelliferyl) glycosides of GlcNAc and CB, while the CB-bound fraction quenched only the glycoside of CB; other 04-methylumbelliferyl-glycosides were not quenched. Among eleven monosaccharides and oligosaccharides, only GlcNAc, CB, and tri-Nacetylchitotriose were able to inhibit the precipitation of antibodies against CB with CB-protein conjugate. These antibodies failed to agglutinate erythrocytes from various species but did agglutinate transformed cells and mouse lymphocytes. The binding of these antibodies on cell membranes was reversed by free CB and by CB-protein conjugates. The properties of these antibodies are related to those of lectins with similar specificities and to the structure of glycoconjugates. cell agglutination induced by wheat germ lectin (WGA), (2-4); it is known that several tumor cell lines were highly agglutinable by WGA but nontransformed cells were not (2, 5). (iii) In some carbohydrate inhibition experiments, it was found that GlcNAc and CB were the immunodominant group of carcinoembryonic antigen (6-8), however, opposite results were found by other authors (9, 10). (iv) CB glycosidically linked to poly-L-aspartate via N-asparaginyl bonds was shown to elicit an immune response which increased the survival times of mice challenged with an intraperitoneal injection of tumor cells (11). Di-N-acetylchitobiose (CBTo detect and to study the functions of cell surface glycoconjugates, lectins have been extensively used (12, 13). However, on one hand, lectins are usually tetravalent as WGA is (14-16) and therefore lectins agglutinate cells or crosslink the cell surface glycoconjugate; on the other hand, lectins bind large oligosaccharides and glycoproteins more strongly than monosaccharides or small oligosaccharides (13). Recently, carbohydrate specific antibodies were purified from the sera of various animal species by affinity chromatography on immobilized fetuin as an adsorbent (17); the binding of carbohydrate specific antibodies to mouse splenocytes was partially inhibited by various free sugars and by several oligosaccharides. Antibodies raised against some specific oligosaccharides should be a sugar-binding protein with narrow specificity, and Fab fragments easily obtained by proteolytic hydrolysis of the antibodies should be...

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Fetuin: Immunochemistry and quantitative estimation in serum

Cited by 82 publications

References 16 publications

Distribution of bovine fetuin and albumin in plasma, allantoic and amniotic fluids during development

Distribution of bovine fetuin and albumin in plasma, allantoic and amniotic fluids during development

Antibodies reactive with cell surface carbohydrates.

Protein-sugar interactions: preparation, purification, and properties of rabbit antibodies against di-N-acetylchitobiose.

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