scholarly journals The isolation of ovomucoid variants differing in carbohydrate composition

1971 ◽  
Vol 123 (3) ◽  
pp. 399-405 ◽  
Author(s):  
J. G. Beeley
Keyword(s):  
Sialic Acid ◽  
Amino Acid ◽  
Acid Content ◽  
Deae Cellulose ◽  
Structure And Function ◽  
Inhibiting Activity ◽  
Carbohydrate Composition ◽  
Charge Heterogeneity ◽  
Sialic Acid Content ◽  
And Function

Three major and two minor species of ovomucoid were separated by chromatography on sulphoethyl-Sephadex. The predominant sialic acid-free species was further resolved into three fractions by DEAE-cellulose chromatography. Although all species of ovomucoid had closely similar trypsin-inhibiting activity, immunochemical properties and amino acid composition, they differ in carbohydrate composition. Wide variation was observed in the content of galactose, N-acetylglucosamine and sialic acid. Charge heterogeneity was related, in part, to variation in sialic acid content. The implications of variable carbohydrate composition for the structure and function of ovomucoid are discussed.

scholarly journals Effects of variant gamma chains and sialic acid content of fibrinogen upon its interactions with ADP-stimulated human and rabbit platelets

Blood ◽  
1984 ◽  
Vol 64 (6) ◽  
pp. 1163-1168 ◽  
Author(s):  
EJ Harfenist ◽  
MA Packham ◽  
JF Mustard
Keyword(s):  
Sialic Acid ◽  
Acid Content ◽  
Deae Cellulose ◽  
Adenosine Diphosphate ◽  
Gamma Chain ◽  
Sialic Acid Content ◽  
Human Fibrinogen ◽  
Rabbit Platelets ◽  
Chain Composition ◽  
Normal Human

Abstract When platelets are stimulated with adenosine diphosphate (ADP), fibrinogen binds to receptors on the platelet membrane, and the platelets aggregate. The primary platelet recognition sites of human fibrinogen are reported to be at the COOH-terminal ends of the gamma chains, with secondary sites in the A alpha chains. Normal human fibrinogen, which consists of three pairs of disulfide-bonded peptide chains, (A alpha, B beta, gamma)2, is heterogeneous with respect to sialic acid content and also contains a small proportion of molecules with a variant gamma chain (designated gamma'), elongated by a peptide extension at the COOH-terminus of the normal gamma chain. We separated fibrinogen into three fractions by chromatography on DEAE cellulose and tested the interactions of these fractions with ADP-stimulated human and rabbit platelets. Two fractions had the normal chain composition, (A alpha B beta, gamma)2, but different sialic acid contents (6.6 and 7.2 mol/mol), and the third fraction had the chain composition (A alpha, B beta)2 gamma gamma' and a sialic acid content of 7.2 mol/mol, which is similar to that of one of the normal fractions. In binding and aggregation experiments, we detected no significant differences between the reactions of the first two fractions, but ADP-stimulated platelets bound only 50% as much of 125I-fibrinogen from the fraction with the gamma' chains and also aggregated less extensively in the presence of this fraction. We conclude that the sialic acid content of fibrinogen does not significantly affect its interactions with platelets, but the elongated gamma' chains bind less effectively to ADP-stimulated platelets, and thus reduce the ability of fibrinogen to support aggregation. This may result from a conformational change caused by the gamma' extension or from the deletion of a portion of the normal gamma chain recognition site.

THE EFFECTS OF SIALIDASE ON PSEUDOCHOLINESTERASE TYPES

1963 ◽  
Vol 41 (1) ◽  
pp. 969-974 ◽  
Author(s):  
D. J. Ecobichon ◽  
W. Kalow
Keyword(s):  
Sialic Acid ◽  
Amino Acid ◽  
Human Serum ◽  
Acid Content ◽  
Protein Molecule ◽  
Serum Cholinesterase ◽  
Kinetic Properties ◽  
Sialic Acid Content ◽  
Starch Gel ◽  
A Charge

Hereditary variants of human serum cholinesterase were exposed to the action of sialidase. The removal of the sialic acid residues had no effect on the kinetic properties of the esterases but greatly affected the electrophoretic mobility. In starch gel, there were no differences between the pseudocholinesterase types whether sialidase-treated or untreated. This observation permits two conclusions: first, the differences between the esterase types must reside in the protein cores, and second, the different variants must possess equal amounts of sialic acid per protein molecule. According to Liddell et al. there is a charge difference between esterase molecules of different type; since this cannot be accounted for by sialic acid content, the distinguishing characteristics are likely due to differences of amino acid composition.

scholarly journals The influence of sialic acid residues on the ability of glycoproteins toi nteract electrostatically with chondromucoprotein

1965 ◽  
Vol 97 (2) ◽  
pp. 333-339 ◽  
Author(s):  
AJ Anderson
Keyword(s):  
Sialic Acid ◽  
Complex Formation ◽  
Acid Hydrolysis ◽  
Acid Content ◽  
Biological Activities ◽  
Carbohydrate Composition ◽  
Mild Acid Hydrolysis ◽  
Sialic Acid Content ◽  
Neuraminidase Treatment ◽  
Mild Acid

1. Although glycoproteins with less than 1% of sialic acid (fibrinogen, lipoproteins, gamma-globulins) interact electrostatically with chondromucoprotein to form insoluble complexes, interaction with glycoproteins containing larger amounts of sialic acid (orosomucoid, urine glycoprotein, seromucoid, fraction VI) was electrostatically impossible. Reasons for this are discussed. 2. The latter glycoproteins interacted with chondromucoprotein after mild acid hydrolysis or neuraminidase treatment, complex-formation being inversely related to their sialic acid content. 3. Complex-formation with sialic acid-deficient orosomucoid was maximum at pH3.6 and negligible above its isoelectric point of pH5, and was inhibited by Ca(2+) ions and EDTA. 4. These results are discussed in relation to the carbohydrate composition and biological activities of euglobulin fractions, and of complexes formed by adding chondromucoprotein to abnormal plasmas which may contain sialic acid-deficient glycoproteins owing to faulty carbohydrate metabolism.

THE EFFECTS OF SIALIDASE ON PSEUDOCHOLINESTERASE TYPES

1963 ◽  
Vol 41 (4) ◽  
pp. 969-974 ◽  
Author(s):  
D. J. Ecobichon ◽  
W. Kalow
Keyword(s):  
Sialic Acid ◽  
Amino Acid ◽  
Human Serum ◽  
Acid Content ◽  
Protein Molecule ◽  
Serum Cholinesterase ◽  
Kinetic Properties ◽  
Sialic Acid Content ◽  
Starch Gel ◽  
A Charge

Hereditary variants of human serum cholinesterase were exposed to the action of sialidase. The removal of the sialic acid residues had no effect on the kinetic properties of the esterases but greatly affected the electrophoretic mobility. In starch gel, there were no differences between the pseudocholinesterase types whether sialidase-treated or untreated. This observation permits two conclusions: first, the differences between the esterase types must reside in the protein cores, and second, the different variants must possess equal amounts of sialic acid per protein molecule. According to Liddell et al. there is a charge difference between esterase molecules of different type; since this cannot be accounted for by sialic acid content, the distinguishing characteristics are likely due to differences of amino acid composition.

scholarly journals The sialic acid content and isoelectric point of human kininogen

1975 ◽  
Vol 145 (2) ◽  
pp. 401-403 ◽  
Author(s):  
J C Londesborough ◽  
U Hamberg
Keyword(s):  
Molecular Weight ◽  
Sialic Acid ◽  
Amino Acid ◽  
Isoelectric Point ◽  
Acid Content ◽  
Low Molecular Weight ◽  
Sialic Acid Content

The sialic acid content of highly purified human kininogen was found to be about 8.6 mol/mol(mol.wt. 50,000). The isoelectric point (pH 4.9 +/- 0.2) is much higher than that of bovine low-molecular-weight kininogen, but is close to that expected from the amino acid and sialic acid analyses.

scholarly journals Differential sialic acid content in adult and neonatal fibrinogen mediates differences in clot polymerization dynamics

2021 ◽  
Author(s):  
Kimberly Nellenbach ◽  
Alexander Kyu ◽  
Nina Guzzetta ◽  
Ashley Brown
Keyword(s):  
Sialic Acid ◽  
Acid Content ◽  
Fibrin Clot ◽  
Fibrinopeptide A ◽  
Sialic Acid Content ◽  
Fibrin Polymerization ◽  
Fibrin Networks ◽  
Molecular Variant ◽  
Mixed Efficacy ◽  
And Function

Neonates possess a molecular variant of fibrinogen, known as fetal fibrinogen, characterized by increased sialic acid, a greater negative charge, and decreased activity compared to adults. Despite these differences, adult fibrinogen is used for treatment of bleeding in neonates, with mixed efficacy. In order to determine safe and efficacious bleeding protocols for neonates, more information on neonatal fibrin clot formation and the influence of sialic acid on these processes is needed. Here, we examine the influence of sialic acid on neonatal fibrin polymerization. We hypothesized that the increased sialic acid content of neonatal fibrinogen promotes fibrin B:b knob hole interactions and consequently influences the structure and function of the neonatal fibrin matrix. We explored this hypothesis through analysis of structural properties and knob:hole polymerization dynamics of normal and desialylated neonatal fibrin networks and compare to those formed with adult fibrinogen. We then characterized normal neonatal fibrin knob:hole interactions by forming neonatal and adult clots with either thrombin or snake-venom thrombin like enzymes (SVTLEs) that preferentially cleave fibrinopeptide A or B. We determined that sialic acid content of neonatal fibrinogen is a key determinant of resulting clot properties. Experiments analyzing knob:hole dynamics indicated typical neonatal fibrin clots are formed with the release of more fibrinopeptide B and less fibrinopeptide A than adults. After the removal of sialic acid, fibrinopeptide release was roughly equivalent between adults and neonates indicating the influence of sialic acid on fibrin neonatal fibrin polymerization mechanisms. These results could inform future studies developing neonatal specific treatments of bleeding.

scholarly journals Effects of variant gamma chains and sialic acid content of fibrinogen upon its interactions with ADP-stimulated human and rabbit platelets

Blood ◽  
1984 ◽  
Vol 64 (6) ◽  
pp. 1163-1168
Author(s):  
EJ Harfenist ◽  
MA Packham ◽  
JF Mustard
Keyword(s):  
Sialic Acid ◽  
Acid Content ◽  
Deae Cellulose ◽  
Adenosine Diphosphate ◽  
Gamma Chain ◽  
Sialic Acid Content ◽  
Human Fibrinogen ◽  
Rabbit Platelets ◽  
Chain Composition ◽  
Normal Human

When platelets are stimulated with adenosine diphosphate (ADP), fibrinogen binds to receptors on the platelet membrane, and the platelets aggregate. The primary platelet recognition sites of human fibrinogen are reported to be at the COOH-terminal ends of the gamma chains, with secondary sites in the A alpha chains. Normal human fibrinogen, which consists of three pairs of disulfide-bonded peptide chains, (A alpha, B beta, gamma)2, is heterogeneous with respect to sialic acid content and also contains a small proportion of molecules with a variant gamma chain (designated gamma'), elongated by a peptide extension at the COOH-terminus of the normal gamma chain. We separated fibrinogen into three fractions by chromatography on DEAE cellulose and tested the interactions of these fractions with ADP-stimulated human and rabbit platelets. Two fractions had the normal chain composition, (A alpha B beta, gamma)2, but different sialic acid contents (6.6 and 7.2 mol/mol), and the third fraction had the chain composition (A alpha, B beta)2 gamma gamma' and a sialic acid content of 7.2 mol/mol, which is similar to that of one of the normal fractions. In binding and aggregation experiments, we detected no significant differences between the reactions of the first two fractions, but ADP-stimulated platelets bound only 50% as much of 125I-fibrinogen from the fraction with the gamma' chains and also aggregated less extensively in the presence of this fraction. We conclude that the sialic acid content of fibrinogen does not significantly affect its interactions with platelets, but the elongated gamma' chains bind less effectively to ADP-stimulated platelets, and thus reduce the ability of fibrinogen to support aggregation. This may result from a conformational change caused by the gamma' extension or from the deletion of a portion of the normal gamma chain recognition site.

129: Sialic Acid Content of Urinary TAMM-Horsfall Protein is Reduced in Interstitial Cystitis Patients

2007 ◽  
Vol 177 (4S) ◽  
pp. 44-45
Author(s):  
C. Lowell Parsons ◽  
Mahadevan Rajasekaran ◽  
Marianne Chenoweth ◽  
Paul Stein
Keyword(s):  
Sialic Acid ◽  
Interstitial Cystitis ◽  
Acid Content ◽  
Sialic Acid Content
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