A method for the simultaneous estimation of free and ketosidically bound sialic acids

1977 ◽  
Vol 55 (7) ◽  
pp. 778-782 ◽  
Author(s):  
C. F. A. Culling ◽  
P. E. Reid ◽  
C. W. Ramey ◽  
W. L. Dunn ◽  
M. G. Clay
Keyword(s):  
Sialic Acid ◽  
Room Temperature ◽  
Thiobarbituric Acid ◽  
Sialic Acids ◽  
Simultaneous Estimation ◽  
Sodium Metaperiodate ◽  
Acetylneuraminic Acid ◽  
Acid Reagent ◽  
Bovine Submaxillary Mucin ◽  
Free Sialic Acid

Various methods for the estimation of free and ketosidically bound sialic acid were investigated for accuracy and specificity. It was found that oxidation with 0.025 M sodium metaperiodate in pH 7.0 phosphate buffer at room temperature for 20 min provided a simple, rapid, sensitive method whereby both the free and the ketosidically bound acid present in a mixture could be quantitatively analyzed. On completion of the oxidation step, the bound sialic acid is estimated with resorcinol reagent and the free sialic acid with thiobarbituric acid reagent. Oxidation under these conditions permitted a facile analysis of mixtures of bovine submaxillary mucin and free N-acetylneuraminic acid, whereas the Warren thiobarbituric acid procedure gave an erroneous value for free sialic acid.

scholarly journals Stable thiobarbituric acid chromophore with dimethyl sulphoxide. Application to sialic acid assay in analytical de-O-acetylation

1976 ◽  
Vol 159 (3) ◽  
pp. 457-462 ◽  
Author(s):  
L Skoza ◽  
S Mohos
Keyword(s):  
Sialic Acid ◽  
Homogeneous Solution ◽  
Thiobarbituric Acid ◽  
Alkaline Treatment ◽  
Dimethyl Sulphoxide ◽  
Optimal Conditions ◽  
Test Mixture ◽  
Acetylneuraminic Acid ◽  
Thiobarbituric Acid Assay ◽  
Bovine Submaxillary Mucin

With dimethyl sulphoxide instead of butanol in the thiobarbituric acid assay for sialic acid, a non-fading chromophore with lambdamax. = 549 nm was produced in a homogeneous solution, allowing dilution of the test mixture in case of high colour yield. This test adapted well to studies on alkaline de-O-acetylation. Bovine and rat submaxillary mucins, and rabbit Tamm-Horsfall urinary sialoproteins contain O-acetyl isomers of neuramine acid that are resistant to the thiobarbituric acid assay. Alkaline de-O-acetylation converted resistant O-acetylneuraminic acid into thiobarbituric acid-reactive sialic acid, and such conversion paralleled de-O-acetylation as measured by the ferric hydroxamate method. The colour increment was similar when the alkaline treatment of bovine submaxillary mucin either preceded or followed the acid hydrolysis. Only alkaline preptreatment was effective with rat submaxillary mucin. By selecting optimal conditions for alkaline de-O-acetylation, O-acetyl isomers can be accurately assessed by the thiobarbituric acid assay.

scholarly journals Identification of N-acetyl-4–O-acetylneuraminyl-lactose in echidna milk

1974 ◽  
Vol 139 (2) ◽  
pp. 415-420 ◽  
Author(s):  
Michael Messer
Keyword(s):  
Sialic Acid ◽  
Acid Hydrolysis ◽  
Acid Treatment ◽  
Periodate Oxidation ◽  
Thiobarbituric Acid ◽  
Chromatographic Mobility ◽  
Mild Acid Hydrolysis ◽  
Acetylneuraminic Acid ◽  
Acid Reagent ◽  
Mild Acid

The identity of a novel form of sialyl-lactose found in milk of the echidna (Tachyglossus aculeatus) was investigated. The sialyl-lactose yielded equimolar amounts of N-acetylneuraminic acid and lactose during mild acid hydrolysis but was resistant to the action of a bacterial neuraminidase. A viral neuraminidase hydrolysed it to lactose plus a form of sialic acid that reacted positively with thiobarbituric acid reagent but whose chromatographic mobility was greater than that of N-acetylneuraminic acid. Treatment with alkali converted the sialyl-lactose into a substance with the same chromatographic mobility as N-acetylneuraminyl-(2→3)-lactose and made it susceptible to the action of bacterial neuraminidase. The sialyl-lactose contained one mol of ester (identified as acetyl), and released one mol of formaldehyde during periodate oxidation, per mol of sialic acid. It did not contain N-glycollylneuraminic acid. These results indicate that the sialyl-lactose is N-acetyl-4-O-acetylneuraminyl-(2→3)-lactose. Echidna milk contained, in addition, a small amount of N-acetylneuraminyl-(2→3)-lactose.

scholarly journals Sialidases from gut bacteria: a mini-review

2016 ◽  
Vol 44 (1) ◽  
pp. 166-175 ◽  
Author(s):  
Nathalie Juge ◽  
Louise Tailford ◽  
C David Owen
Keyword(s):  
Sialic Acid ◽  
Pathogenic Bacteria ◽  
Current Knowledge ◽  
Enzymatic Reaction ◽  
Biochemical Properties ◽  
Sialic Acids ◽  
Gut Bacteria ◽  
Acetylneuraminic Acid ◽  
Acid Reaction ◽  
Free Sialic Acid

Sialidases are a large group of enzymes, the majority of which catalyses the cleavage of terminal sialic acids from complex carbohydrates on glycoproteins or glycolipids. In the gastrointestinal (GI) tract, sialic acid residues are mostly found in terminal location of mucins via α2-3/6 glycosidic linkages. Many enteric commensal and pathogenic bacteria can utilize sialic acids as a nutrient source, but not all express the sialidases that are required to release free sialic acid. Sialidases encoded by gut bacteria vary in terms of their substrate specificity and their enzymatic reaction. Most are hydrolytic sialidases, which release free sialic acid from sialylated substrates. However, there are also examples with transglycosylation activities. Recently, a third class of sialidases, intramolecular trans-sialidase (IT-sialidase), has been discovered in gut microbiota, releasing (2,7-anhydro-Neu5Ac) 2,7-anydro-N-acetylneuraminic acid instead of sialic acid. Reaction specificity varies, with hydrolytic sialidases demonstrating broad activity against α2,3-, α2,6- and α2,8-linked substrates, whereas IT-sialidases tend to be specific for α2,3-linked substrates. In this mini-review, we summarize the current knowledge on the structural and biochemical properties of sialidases involved in the interaction between gut bacteria and epithelial surfaces.

Sialic Acid (N-Acetylneuraminic Acid) in Human Serum

1964 ◽  
Vol 10 (11) ◽  
pp. 986-990 ◽  
Author(s):  
J A Cabezas ◽  
J Vazquez Porto
Keyword(s):  
Sialic Acid ◽  
Rheumatic Disease ◽  
Human Serum ◽  
Spectrophotometric Method ◽  
Butyl Acetate ◽  
Normal Values ◽  
Sialic Acids ◽  
Old Adults ◽  
Acetylneuraminic Acid ◽  
Severe Burns

Abstract A simple spectrophotometric method is described for the sialic acids which utilizes the reaction with resorcinol and extraction with butyl acetate-n-butanol as a solvent. Normal values for adults, utilizing N-acetylneuraminic acid as a standard, were found to be 60 ± 10.4 mg./100 ml. Values for newborn babies averaged 40.4 ± 5.7. Similar values were found for specimens from 2-month-old infants to 27-year-old adults. Higher values were noted in the case of rickets, severe burns, rheumatic disease, and tuberculosis.

scholarly journals Sialic acid acquisition in bacteria–one substrate, many transporters

2016 ◽  
Vol 44 (3) ◽  
pp. 760-765 ◽  
Author(s):  
Gavin H. Thomas
Keyword(s):  
Sialic Acid ◽  
Immune Evasion ◽  
Sialic Acids ◽  
Major Facilitator Superfamily ◽  
Acid Uptake ◽  
Gram Negative Bacteria ◽  
Acetylneuraminic Acid ◽  
Wide Range ◽  
Major Facilitator

The sialic acids are a family of 9-carbon sugar acids found predominantly on the cell-surface glycans of humans and other animals within the Deuterostomes and are also used in the biology of a wide range of bacteria that often live in association with these animals. For many bacteria sialic acids are simply a convenient source of food, whereas for some pathogens they are also used in immune evasion strategies. Many bacteria that use sialic acids derive them from the environment and so are dependent on sialic acid uptake. In this mini-review I will describe the discovery and characterization of bacterial sialic acids transporters, revealing that they have evolved multiple times across multiple diverse families of transporters, including the ATP-binding cassette (ABC), tripartite ATP-independent periplasmic (TRAP), major facilitator superfamily (MFS) and sodium solute symporter (SSS) transporter families. In addition there is evidence for protein-mediated transport of sialic acids across the outer membrane of Gram negative bacteria, which can be coupled to periplasmic processing of different sialic acids to the most common form, β-D-N-acetylneuraminic acid (Neu5Ac) that is most frequently taken up into the cell.

scholarly journals Metabolism of sialic acid in regenerating rat liver

1980 ◽  
Vol 188 (3) ◽  
pp. 905-911 ◽  
Author(s):  
Y Okamoto ◽  
N Akamatsu
Keyword(s):  
Sialic Acid ◽  
Partial Hepatectomy ◽  
Rat Liver ◽  
Similar Pattern ◽  
Early Stage ◽  
Acetylneuraminic Acid ◽  
Control Value ◽  
Liver Slices ◽  
Regenerating Rat Liver ◽  
Free Sialic Acid

In regenerating rat liver slices 24 h after partial hepatectomy, the incorporation of [1-14C]glucosamine into ‘free sialic acid’ (N-acetylneuraminic acid + CMP-N-acetylneuraminic acid) decreased to below 50% of the control values and the incorporation into protein-bound sialic acid decreased to the same extent. The incorporation of [14C]glucosamine into ‘free sialic acid’ decreased during the period from 6 to 47 h after hepatectomy, showing a minimum at 12 h, and recovered to the control value by 96 h. At 12 h, the activities of UDP-N-acetylglucosamine 2-epimerase (UDP-2-acetoamido-2-deoxy-D-glucose 2-epimerase, EC 5.1.3.14) and N-acyl-D-mannosamine kinase (ATP: 2-acylamino-2-deoxy-D-mannose 6-phosphotransferase, EC 2.7.1.60) in the liver were significantly decreased. The amount of protein-bound sialic acid in the liver was not changed after partial hepatectomy, but the amount in plasma was changed, with a similar pattern to that of the incorporation of [14C]glucosamine into slice ‘free sialic acid’. These results indicate that the synthesis of sialic acid in the liver much decreases in the early stage of regeneration and that this may be correlated with the decreased synthesis of plasma sialoglycoproteins.

scholarly journals Elucidation of the topological parameters of N-acetylneuraminic acid and some analogues involved in their interaction with the N-acetylneuraminate lyase from Clostridium perfringens

1992 ◽  
Vol 282 (2) ◽  
pp. 511-516 ◽  
Author(s):  
E Zbiral ◽  
R G Kleineidam ◽  
E Schreiner ◽  
M Hartmann ◽  
R Christian ◽  
...  
Keyword(s):  
Sialic Acid ◽  
Oxygen Atom ◽  
Clostridium Perfringens ◽  
Pyruvic Acid ◽  
Sialic Acids ◽  
Side Chain ◽  
Equatorial Zone ◽  
Enzyme Action ◽  
Acetylneuraminic Acid ◽  
Topological Parameters

A series of neuraminic acid derivatives modified in the side chain or at C-3, C-4 or C-5 were tested as substrates of inhibitors of N-acetylneuraminate lyase (EC 4.1.3.3) from Clostridium perfringens. The results, together with Km and Ki values reported previously, indicate that the region most important for the binding of sialic acids is an equatorial zone reaching from C-8 via the ring oxygen atom to C-4 of the sugar molecule, whereas the substituents at C-9 and C-5 may be varied to a higher extent without significantly disturbing enzyme action. It is shown that stereo-electronic factors are responsible for the immediate heterolytic fragmentation of the cyclic sialic acid into pyruvic acid and 2-acetamidomannose or a related C-6 sugar.

The Inhibitory Effect of Sialic Acid on Fibrinolysis

1967 ◽  
Vol 17 (01/02) ◽  
pp. 023-030 ◽  
Author(s):  
H Rubin ◽  
N. D Ritz
Keyword(s):  
Sialic Acid ◽  
Inhibitory Effect ◽  
Sialic Acids ◽  
Normal Serum ◽  
The Body ◽  
Inhibitory Effects ◽  
Acetylneuraminic Acid ◽  
Heated Plates ◽  
Hydrolysis Of ◽  
Fibrinolytic Action

SummaryThe inhibitory effect of N-acetylneuraminic acid and glycolyl neuramaminic acids on the hydrolysis of 51Cr tagged casein by plasmin and α-chymotrypsin has been demonstrated. N,O-diacetylneuraminic acid was ineffective. The inhibitory effect was increased by an increase in ionic strength of the reaction mixture. The two active sialic acids also inhibited the fibrinolytic action of human plasmin on heated and unheated bovine fibrin plates. The greater inhibition noted on heated plates may indicate a primary effect on plasmin rather than on activators of plasmin. The inhibitory effects of N-acetyl neuraminic acid appeared to be potentiated by normal serum inhibitors. Sialic acid did not influence the conversion of fibrin monomer to polymer.N-acetylneuraminic acid may play an important role in preserving the integrity of fibrin deposits in the body.

Ginsenosides, potent inhibitors of sialyltransferase

2020 ◽  
Vol 75 (1-2) ◽  
pp. 41-49 ◽  
Author(s):  
Wenxin Huang ◽  
Liwen Sun ◽  
Baihui Wang ◽  
Yan Ma ◽  
Dahong Yao ◽  
...  
Keyword(s):  
Sialic Acid ◽  
Cancer Cells ◽  
Theoretical Foundation ◽  
Acid Synthesis ◽  
Dose Dependence ◽  
Sialic Acids ◽  
Enzyme Linked Immunosorbent Assay ◽  
Liver Cancer Cells ◽  
Free Sialic Acid ◽  
Different Levels

AbstractThe overexpression of sialic acids and sialyltransferases (STs) during malignant transformation and progression could result in the aberrant sialylation of cancer cells. Therefore, interfering the sialic acid synthesis might be an effective pathway in cancer therapy. In this study, we assessed that the antitumor inhibitors of 20(S)-ginsenosides Rg3, 20(R)-ginsenosides Rg3, 20(S)-ginsenosides Rh2, and 20(R)-ginsenosides Rh2 could block the sialoglycans in liver cancer cells HepG2. The results showed that these four compounds could inhibit the expressions of the total and free sialic acid at different levels in HepG2, respectively; also, it showed dose dependence. In addition, the results of the enzyme-linked immunosorbent assay showed that the above four compounds can inhibit the expression of STs significantly. We also found that these compounds could mediate the block of sialylation of α2,3- and α2,6-linked sialic acids in HepG2 cells by flow cytometry. Meanwhile, the results of the molecular docking investigation showed that these compounds showed strong interaction with ST6GalI and ST3GalI. These results verified that the ginsenosides have a powerful inhibiting aberrant sialylation, and it laid a theoretical foundation for further research on the investigation of ginsenosides as the target inhibitors on STs.

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