Removal of O-acetylated sialic acids from rat colonic epithelial glycoproteins by cell-free extracts of rat faeces

Sterile, cell-free, extracts of freshly defaecated Wistar rat faeces in a pH 7.0 "minimal medium" contain neuraminidase(s), capable of removing sialic acids both with and without side-chain substituents from bovine submandibular mucin and rat colonic epithelial glycoproteins, and an esterase which removes O-acetyl substituents from the side chain of sialic acid residues. Studies of the removal of sialic acids from bovine submandibular mucin and rat colonic epithelial glycoproteins indicated that (i) the faecal enzymes removed a greater proportion of the sialic acid of both the de-O-acetylated and native glycoproteins than was removed with Vibrio cholera neuraminidase, (ii) sialic acids were removed more rapidly from de-O-acetylated glycoproteins, and (iii) the resistance to removal of sialic acids was apparently dependent at least in part upon the O-acetyl sialic acid content of the substrate.

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Erythrocyte Sialic Acid Content during Aging in Humans: Correlation with Markers of Oxidative Stress

Disease Markers ◽

10.1155/2012/293429 ◽

2012 ◽

Vol 32 (3) ◽

pp. 179-186 ◽

Cited By ~ 28

Author(s):

Mohammad Murtaza Mehdi ◽

Prabhakar Singh ◽

Syed Ibrahim Rizvi

Keyword(s):

Oxidative Stress ◽

Sialic Acid ◽

Erythrocyte Membrane ◽

Acid Content ◽

Lipid Hydroperoxide ◽

Plasma Lipid ◽

Sialic Acids ◽

Sialic Acid Content ◽

Total Antioxidant ◽

The Relationship

Sialic acids are substituted neuraminic acid derivatives which are typically found at the outermost end of glycan chains on the membrane in all cell types. The role of erythrocyte membrane sialic acids during aging has been established however the relationship between sialic acid and oxidative stress is not fully understood. The present work was undertaken to analyze the relationship between erythrocyte membrane sialic acid with its plasma level, membrane and plasma lipid hydroperoxide levels and plasma total antioxidant capacity. Results show that sialic acid content decreases significantly (P< 0.001) in RBC membrane (r= −0.901) and increases in plasma (r= 0.860) as a function of age in humans. Lipid peroxidation measured in the form of hydroperoxides increases significantly (P< 0.001) in plasma (r= 0.830) and RBC membranes (r= 0.875) with age in humans. The Trolox Equivalent Total Antioxidant Capacity (TETAC) of plasma was found to be significantly decreased (P< 0.001,r= −0.844). We observe significant correlations between decrease of erythrocyte membrane sialic acid and plasma lipid hydroperoxide and TETAC. Based on the observed correlations, we hypothesize that increase in oxidative stress during aging may influence the sialic acid decomposition from membrane thereby altering the membrane configuration affecting many enzymatic and transporter activities. Considering the importance of plasma sialic acid as a diagnostic parameter, it is important to establish age-dependent reference.

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Correction of the Delayed Fibrin Aggregation of Fetal Fibrinogen by Partial Removal of Sialic Acid

10.1055/s-0039-1684458 ◽

1979 ◽

Author(s):

D.K. Galanakis ◽

M.W. Mosesson

Keyword(s):

Sialic Acid ◽

Acid Content ◽

Acid Value ◽

Full Term ◽

Thrombin Time ◽

Sialic Acid Content ◽

Vibrio Cholera ◽

The Mean ◽

Fraction I ◽

Free Sialic Acid

Human umbilical oord fibrinogen characteristically displays delayed fibrin aggregation under conditions of relatively high ionic strength. This delay is greater in fibrinogen obtained from premature (p) (24–35 weeks gestation) infants, as compared with that from full term (FT) infants. We compared the sialic acid content of (fraction I-2) fetal (P and FT) with adult (A) fibrinogen, obtained from pooled plasma. The mean sialic acid μg/100mg protein) values were: P, 818 (±135 SD, range 621–1030); FT, 720 (±212, range 505–1280); A, 626 (±110, range 487-806). One P fibrinogen preparation (thrombin time 22.6 seconds) was partially desialated (resulting sialic acid value 490) by incubation with Vibrio cholera neuraminidase, dialyzed , and precipitated with ethanol to remove free sialic acid. The thrombin time of the resulting preparation was 15.4 (range 15.2–15.8), compared to 16.1 (range 15.5–16.4) for untreated A fibrinogen. The results suggest that the delayed fibrin aggregation of fetal fibrinogen is attributable to its relatively high sialic acid content. Moreover, the intermediate sialic acid (and thrombin time) values of FT (as compared to those of p) fibrinogen intimate the presence of a mixture of adult and fetal fibrinogen in full term cord blood.

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Sialoglycoproteins and sialic acids ofPlasmodium knowlesischizont-infected erythrocytes and normal rhesus monkey erythrocytes

Parasitology ◽

10.1017/s0031182000065422 ◽

1986 ◽

Vol 92 (3) ◽

pp. 527-543 ◽

Cited By ~ 7

Author(s):

R. J. Howard ◽

G. Reuter ◽

J. W. Barnwell ◽

R. Schauer

Keyword(s):

Sialic Acid ◽

Rhesus Monkey ◽

Acid Content ◽

Sialic Acids ◽

Galactose Oxidase ◽

Parasite Development ◽

Sialic Acid Content ◽

Acetylneuraminic Acid ◽

Total Sialic Acid ◽

Significant Difference

SUMMARYThe effects of malaria infection on RBC sialic acids and sialoglycoproteins were studied with asexual blood-stage infections ofPlasmodium knowlesiin rhesus monkeys. Glycoprotein radio-isotope labelling methods were used to compare the sialoglycoproteins of normal RBC andP. knowlesischizont-infected RBC (SI-RBC). Tritiation of glycoproteins from SI-RBC with the standard sialidase + galactose oxidase/NaB3H4method or standard periodate/NaB3H4method was significantly decreased when compared to normal RBC. However, tritium uptake into glycoproteins was normal when SI-RBC were treated with 5-fold higher concentrations of both enzymes in the first labelling method, or with a 5-fold increase in the molar ratio of periodate to sialic acid in the second method. The mobility of tritiated host cell glycoproteins on SDS–polyacrylamide gels was identical for SI-RBC and normal RBC. New bands, possibly glycoproteins, of 230, 160, 90, 52, and 30 kDa were detected after labelling SI-RBC by the modified periodate/NaB3H4method. Sialic acid analysis of normal rhesus monkey RBC (62μg/1010RBC) revealed that 46% of the total sialic acid wasN-glycolylneuraminic acid, 33% wasN-acetyl-9-O-acetylneuraminic acid, and the remainderN-acetylneuraminic acid. SI-RBC collected either directly from infected monkeys or afterin vitroculture of ring-infected RBC in horse serum, had increased total sialic acid (126 or 115μg/1010RBC, respectively). The sialic acid content of infected RBC must increase during parasite development since RBC infected with ring-stageP. knowlesihad the same content as normal RBC. There was no significant difference in the ratio of the three sialic acids of SI-RBC and normal RBC. In contrast, the uninfected RBC from infected blood of different monkeys showed marked variation in sialic acid composition and generally had a lower sialic acid content than normal RBC.

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Sialic Acid Content of Red Blood Cells from Protein-Calorie Malnourished Children and During Recovery, and from Normal Children and Adults

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y73-130 ◽

1973 ◽

Vol 51 (11) ◽

pp. 853-858

Author(s):

C. Contreras ◽

F. E. Viteri

Keyword(s):

Sialic Acid ◽

Acid Content ◽

Recovery Period ◽

Serum Vitamin ◽

Sialic Acids ◽

Red Cells ◽

Control Group ◽

Red Cell ◽

Normal Children ◽

Sialic Acid Content

Sialic acids were measured in the red cells of two groups of subjects. One group consisted of 12 children with severe protein-calorie malnutrition (P.C.M.); six of them were followed longitudinally throughout the recovery period. The control group included 28 normal children and 11 normal adults. All subjects were studied hematologically and the sialic acid content of the red cells was determined in three layers of erythrocytes, separated according to their density by ultracentrifugation. The results indicate that there are no alterations in the content of sialic acids in the red cells of children with severe P.C.M. Furthermore, they show that the sialic acid content of the red cell is not influenced by various levels of red cell folates nor by differences in the concentration of serum proteins, serum iron, percentage saturation of transferrin, serum folates, or serum vitamin B12.

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Sialic Acids in Human Gastric Aspirates: Detection of 9-O-Lactyl- and 9-O-Acetyl-N-Acetylneuraminic Acids and a Decrease in Total Sialic Acid Concentration with Age

Clinical Science ◽

10.1042/cs0840573 ◽

1993 ◽

Vol 84 (5) ◽

pp. 573-579 ◽

Cited By ~ 26

Author(s):

A. P. Corfield ◽

S. A. Wagner ◽

A. Safe ◽

R. A. Mountford ◽

J. R. Clamp ◽

...

Keyword(s):

Sialic Acid ◽

Thin Layer ◽

Acid Content ◽

Colorimetric Assay ◽

Sialic Acids ◽

Gas Chromatography Mass Spectrometry ◽

Sialic Acid Content ◽

Acetylneuraminic Acid ◽

Total Sialic Acid ◽

Thin Layer Chromatographic Analysis

1. The total sialic acid content of human gastric aspirates was measured using a colorimetric assay. Care was taken to optimize the assay and to eliminate interference. 2. The sialic acid content of gastric aspirates collected under resting conditions from 77 patients with non-ulcer dyspepsia was found to decrease with age from >100 μg/ml at 25 years and younger to <20 μg/ml above 70 years of age. 3. Analysis of the sialic acids by gas chromatography, mass spectrometry and thin-layer chromatography showed the presence of N-acetylneuraminic acid and two O-acylated derivatives, 9-O-acetyl- and 9-O-lactyl-N-acetylneuraminic acids. These forms were predominantly glycosidically bound. 4. Thin-layer chromatographic analysis of individual aspirate samples showed that the O-acetylated sialic acids were present in all samples, with a maximum of 25% and a minimum of 5% of the total sialic acids.

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A simple method for the determination of the O-acetyl substitution pattern of the sialic acids of colonic epithelial glycoprotein

Canadian Journal of Biochemistry ◽

10.1139/o77-070 ◽

1977 ◽

Vol 55 (5) ◽

pp. 493-503 ◽

Cited By ~ 24

Author(s):

P. E. Reid ◽

C. F. A. Culling ◽

C. W. Ramey ◽

W. L. Dunn ◽

M. G. Clay

Keyword(s):

Sialic Acid ◽

Sialic Acids ◽

Side Chain ◽

Substitution Pattern ◽

Commercial Sample ◽

Simple Method ◽

Vibrio Cholera ◽

Acyl Substituent ◽

Bovine Submaxillary Mucin

A simple, rapid scheme is described for the quantitative division of the sialic acids of a glycoprotein into four classes: (a) those bearing no O-acyl substituents, (b) those with an O-acyl substituent at position C7, (c) those substituted at C9, and (d) those substituted at C8 or which are either di-(C7C8, C7C9, C8C9) or tri-(C7C8C9) substituted. This scheme can be applied to samples containing as little as 230 μg of sialic acid and requires neither acid hydrolysis nor expensive instrumentation. In combination with previously published techniques it is possible to estimate: (a) the side-chain substitution pattern of those sialic acids which are Vibrio Cholera neuraminidase (EC 3.2.1.18) insensitive, (b) the percentage of sialic acids which are Vibrio Cholera neuraminidase insensitive because of an ester substituent at either position C4 or C1, and (c) the percentage of those sialic acids which bear more than one side-chain substituent.The application of this procedure to epithelial glycoproteins isolated from the colons of man and rat and to a commercial sample of bovine submaxillary mucin is described. Evidence is presented which suggests that either these glycoproteins contain little or no C9-O-acetyl sialic acids and (or) that, under the conditions used, such acids are oxidized to completion.

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