Structural Relationship between Sialic Acid, Neuraminic Acid and 2-Carboxy-Pyrrole

Nature ◽  
1955 ◽  
Vol 176 (4488) ◽  
pp. 881-882 ◽  
Author(s):  
A. GOTTSCHALK
Keyword(s):  
Sialic Acid ◽  
Neuraminic Acid ◽  
Structural Relationship

scholarly journals Designing and Development of FRET-Based Nanosensor for Real Time Analysis of N-Acetyl-5-Neuraminic Acid in Living Cells

2021 ◽  
Vol 8 ◽  
Author(s):  
Ruphi Naz ◽  
Mohammad K. Okla ◽  
Urooj Fatima ◽  
Mohd. Mohsin ◽  
Walid H. Soufan ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Metabolic Engineering ◽  
Sialic Acid ◽  
Real Time ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Neuraminic Acid ◽  
Yeast Cells ◽  
Metabolite Level ◽  
Health Maintenance

N-acetyl-5-neuraminic acid (NeuAc) plays crucial role in improving the growth, brain development, brain health maintenance, and immunity enhancement of infants. Commercially, it is used in the production of antiviral drugs, infant milk formulas, cosmetics, dietary supplements, and pharmaceutical products. Because of the rapidly increasing demand, metabolic engineering approach has attracted increasing attention for NeuAc biosynthesis. However, knowledge of metabolite flux in biosynthetic pathways is one of the major challenges in the practice of metabolic engineering. So, an understanding of the flux of NeuAc is needed to determine its cellular level at real time. The analysis of the flux can only be performed using a tool that has the capacity to measure metabolite level in cells without affecting other metabolic processes. A Fluorescence Resonance Energy Transfer (FRET)-based genetically-encoded nanosensor has been generated in this study to monitor the level of NeuAc in prokaryotic and eukaryotic cells. Sialic acid periplasmic binding protein (SiaP) from Haemophilus influenzae was exploited as a sensory element for the generation of nanosensor. The enhanced cyan fluorescent protein (ECFP) and Venus were used as Fluroscence Resonance Energy Transfer (FRET) pair. The nanosensor, which was termed fluorescent indicator protein for sialic acid (FLIP-SA), was successfully transformed into, and expressed in Escherichia coli BL21 (DE3) cells. The expressed protein of the nanosensor was isolated and purified. The purified nanosensor protein was characterized to assess the affinity, specificity, and stability in the pH range. The developed nanosensor exhibited FRET change after addition to NeuAc. The developed nanosensor was highly specific, exhibited pH stability, and detected NeuAc levels in the nanomolar to milimolar range. FLIP-SA was successfully introduced in bacterial and yeast cells and reported the real-time intracellular levels of NeuAc non-invasively. The FLIP-SA is an excellent tool for the metabolic flux analysis of the NeuAc biosynthetic pathway and, thus, may help unravel the regulatory mechanism of the metabolic pathway of NeuAc. Furthermore, FLIP-SA can be used for the high-throughput screening of E. coli mutant libraries for varied NeuAc production levels.

scholarly journals Kinetic studies on the acid hydrolysis of the methyl ketoside of unsubstituted and O-acetylated N-acetylneuraminic acid

1973 ◽  
Vol 133 (4) ◽  
pp. 623-628 ◽  
Author(s):  
A. Neuberger ◽  
Wendy A. Ratcliffe
Keyword(s):  
Sialic Acid ◽  
Acid Hydrolysis ◽  
Model Compound ◽  
Kinetic Studies ◽  
Order Rate Constant ◽  
Neuraminic Acid ◽  
Acetylneuraminic Acid ◽  
Rate Of Hydrolysis ◽  
Ph Range ◽  
Hydrolysis Of

The hydrolysis of the model compound 2-O-methyl-4,7,8,9-tetra-O-acetyl-N-acetyl-α-d-neuraminic acid and neuraminidase (Vibrio cholerae) closely resembled that of the O-acetylated sialic acid residues of rabbit Tamm–Horsfall glycoprotein. This confirmed that O-acetylation was responsible for the unusually slow rate of acid hydrolysis of O-acetylated sialic acid residues observed in rabbit Tamm–Horsfall glycoprotein and their resistance to hydrolysis by neuraminidase. The first-order rate constant of hydrolysis of 2-methyl-N-acetyl-α-d-neuraminic acid by 0.05m-H2SO4 was 56-fold greater than that of 2-O-methyl-4,7,8,9-tetra-O-acetyl-N-acetyl -α-d-neuraminic acid. Kinetic studies have shown that in the pH range 1.00–3.30, the observed rate of hydrolysis of 2-methyl-N-acetyl-α-d-neuraminic acid can be attributed to acid-catalysed hydrolysis of the negatively charged CO2− form of the methyl ketoside.

Isolation, biochemical and immunological characterisation of two sea urchin glycoproteins bearing sulphated poly(sialic acid) polysaccharides rich in N-glycolyl neuraminic acid

Biochimie ◽  
1996 ◽  
Vol 78 (3) ◽  
pp. 171-182 ◽  
Author(s):  
N.K. Karamanos ◽  
A. Manouras ◽  
S. Anagnostides ◽  
E. Makatsori ◽  
T. Tsegenidis ◽  
...  
Keyword(s):  
Sialic Acid ◽  
Sea Urchin ◽  
Neuraminic Acid

Safety evaluation of the human-identical milk monosaccharide sialic acid (N-acetyl-d-neuraminic acid) in Sprague-Dawley rats

2014 ◽  
Vol 70 (2) ◽  
pp. 482-491 ◽  
Author(s):  
Sharon S.H. Choi ◽  
Nigel Baldwin ◽  
Valentine O. Wagner ◽  
Shambhu Roy ◽  
Jennifer Rose ◽  
...  
Keyword(s):  
Sialic Acid ◽  
Safety Evaluation ◽  
Neuraminic Acid ◽  
Sprague Dawley ◽  
Sprague Dawley Rats

scholarly journals Facile Anomer-oriented Syntheses of 4-Methylumbelliferyl Sialic Acid Glycosides

2021 ◽  
Author(s):  
Abdullah Hassan ◽  
Stefan Oscarson
Keyword(s):  
Catalytic Activity ◽  
Sialic Acid ◽  
Substrate Specificity ◽  
Enzymatic Activity ◽  
Addition Reaction ◽  
Neuraminic Acid ◽  
Acetylneuraminic Acid ◽  
Diastereoselective Addition ◽  
High Yields ◽  
Stereoselective Syntheses

<p>As part of a program to find new sialidases and determine their enzymatic specificity and catalytic activity, a library of 4-methylumbelliferyl sialic acid glycosides derivatised at the C-5 position were prepared from <i>N</i>-acetylneuraminic acid. Both α- and β-4-methylumbelliferyl sialic acid glycosides were prepared in high yields and excellent stereoselectivity. Alpha anomers were accessed via reagent control by utilising additive CH<sub>3</sub>CN and TBAI, whereas the beta anomers were synthesised through a diastereoselective addition reaction of iodine and the aglycone to the corresponding glycal followed by reduction of the resulting 3-iodo compounds. Both anomer-oriented synthetic pathways allow for gram-scale stereoselective syntheses of the desired C-5 modified neuraminic acid derivatives for use as tools to quantify the enzymatic activity and substrate specificity of known<b> </b>sialidases, and potential detection and investigation of<b> </b>novel sialidases.</p>

Localization of neuraminidase-sensitive regions in the Haemophilus pleuropneumoniae Capsule by enzyme-gold affinity cytochemistry

1986 ◽  
Vol 44 ◽  
pp. 310-311
Author(s):  
W. L. Steffens ◽  
S. Kadis ◽  
I. W. Byrd
Keyword(s):  
Sialic Acid ◽  
Respiratory Disease ◽  
Virulence Factor ◽  
Colloidal Gold ◽  
Hydrolytic Enzyme ◽  
Defined Medium ◽  
Etiologic Agent ◽  
Neuraminic Acid ◽  
Chemically Defined Medium

Haemophilus pleuropneumoniae is the etiologic agent of a serious respiratory disease of swine known as porcine Haemophilus pleuropneumonia. There is some evidence suggesting the role of the capsule as a virulence factor in the pathogenesis of the organism and recent investigations have demonstrated and compared the appearance of the capsule in both virulent and avirulent strains by several mucopolysaccharide stains. Our own investigations have demonstrated variability in capsular sensitivity to the hydrolytic enzyme, neuraminidase which cleaves n-acetyl neuraminic acid (sialic acid) from mucins, including those found in several types of bacterial capsules. In an effort to localize the sites of neuraminidase sensitivity within the capsule and to possibly develop a scheme to quantitate the degree of neuraminidase sensitivity among differing serotypes and between cells of similar serotypes grown on complex and chemically defined medium, affinity cytochemistry utilizing colloidal gold-labelled neuraminidase was employed.

The carbohydrate portions of milk glycoproteins

1979 ◽  
Vol 46 (2) ◽  
pp. 187-191 ◽  
Author(s):  
Pierre Jollès
Keyword(s):  
Sialic Acid ◽  
Secondary Structure ◽  
Milk Protein ◽  
Neuraminic Acid ◽  
Bovine Colostrum ◽  
Carbohydrate Moiety ◽  
Cow’S Milk ◽  
Threonine Residue ◽  
Cow's Milk

SUMMARYk-Casein is the main glycoprotein of cow's milk. Its polysaccharide part is O-glycosidically linked to threonine residue 133. It contains only 3 different sugars (Gal, GalNAc, NeuNAc), but a microheterogeneity has been detected at the sugar level. Two main polysaccharides have so far been characterized. The structure of the trisaccharide is NeuNAc α → 3 Gal β1 →3 GalNAc; the tetrasaccharide contains one additional sialic acid. The polysaccharide part of ovine k-casein resembles that of bovine k-casein, but contains also N-glycolyl neuraminic acid. Human k-casein contains 3 times more carbohydrate than bovine k-casein with 2 additional sugars, GlcNAc and Fuc. The various polysaccharide parts isolated from bovine colostrum k-caseinoglycopeptide are much more complex than those obtained from the normal glycopeptide, indicating an evolution of the sugar part as a function of time after parturition. Some aspects of the secondary structure of k-casein and the role of the sugar part are discussed. The carbohydrate moiety of another milk protein, human lactotransferrin, is also discussed briefly. It is comprised of 2 identical glycan groups, N-glycosidically linked to the protein, and quite different from the k-casein carbohydrate moiety.

scholarly journals Boric Acid Catalyzed Methyl Esterification of Sugar Acids

2014 ◽  
Vol 67 (3) ◽  
pp. 528 ◽  
Author(s):  
Stephan M. Levonis ◽  
Brighid B. Pappin ◽  
Alissa Sharp ◽  
Milton J. Kiefel ◽  
Todd A. Houston
Keyword(s):  
Natural Products ◽  
Sialic Acid ◽  
Boric Acid ◽  
Glucuronic Acid ◽  
Quinic Acid ◽  
Neuraminic Acid ◽  
Methyl Esterification ◽  
Acid Catalyzed ◽  
Ulosonic Acid

Boric acid catalyzes methyl esterification of certain sugar acids (sialic acid, deaminated neuraminic acid) and related natural products (quinic acid) quite cleanly in some cases. However, closely related sugar acids (glucuronic acid, 3-deoxy-d-manno-oct-2-ulosonic acid) failed to esterify under the same conditions. Factors governing this dichotomy are discussed.

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