Gangliosides identification

Like in gangliosides, lactones might be found in some bacterial capsular polysaccharides containing 1-carboxyethylsubstituents. But their identification remains problematic due to the conditions of isolation and preparation of analytic samples. To facilitate their detection by NMR, and in order to determine if the formation or hydrolysis of lactones occurred during analytical procedures, synthetic model substances, 2,3- and/or 3,4-lactones based on gluco-12, manno-13, and galactopyranosides 14 were prepared and characterized by NMR spectroscopy (Fig. 2).20 The relative lactonisation rates in acetic acid-fi 4 and hydrolysis rates in buffered D20 were evaluated. 

Hemadsorption binding assay. Identification of ganglioside-bound virus by hemadsorption is performed in Petri dishes incubated with gangliosides, egg albumin and virus as for the water condensation method. After removing unbound virus, to the dish is added... 

G5 BMP-12R Brachyury CBF membrane ganglioside related to pericytes identification receptor to bone morphogenetic protein isoform 12 transcription factor related to embryo mesoderm determination core-binding factor protein family involved in cell differentiation... 

Gilbert M, Brisson JR, Karwaski ME, Michniewicz J, Cunningham AM, Wu Y, Young NM, Wakarchuk WW. Biosynthesis of ganglioside mimics in Campylobacter jejuni OH4384. Identification of the glycosyltransferase genes, enzymatic synthesis of model compounds, and characterization of nanomole amounts by 600-mhz (l)h and (13)c NMR analysis. J. Biol. Chem 2000 275 3896-3906. 

Shapiro, R.E., Specht, C.D., Collins, B.E., Woods, A.S., Cotter, R.J., and Schnaar, R.L. 1997. Identification of a ganglioside recognition domain of tetanus toxin using a novel ganghoside photoaffinity hgand. J. Biol. Chem. 272 30380-30386. 

Nevertheless, chemical characterization of the first gangliosides isolated by these methods led to the identification of their constituent parts. Thus, on hydrolysis, sphingosine, fatty acids, N-acylneuraminic acid, and sugars were obtained. 

Czerkinsky, C.C., and Svennerholm, A.M. (1983) Ganglioside GM1 enzyme linked immunospot assay for simple identification of heat labile enterotoxin producing... 

Specific detection reagents are used for the preliminary identification of glycolipids.The most useful reagents are the resorcinol-HCI spray for gangliosides and the orcinol-sulfuric acid spray for neutral glycolipids and gangliosides. 

Crude preparations of gangliosides have been treated with albumin via a carbodi-imide mediator. The reaction was stopped by precipitation with ammonium sulphate. Following resuspension of the precipitate, unsubstituted albumin was mixed with the albumin-ganglioside conjugate and the suspension treated with glutaraldehyde and then coated onto cellulose filters. These ganglioside affinity filters could be used for the identification of toxigenic strains of Clostridium botulinum types C and D. 

Rementzis, J. Antonopoulou, S. Demopoulos, C.A. (1997). Identification and study of gangliosides from Scomber scombrus muscle. Journal of Agricultural and Food Chemistry, Vol.45, No.3, (March 1997), p>p. 611-615, ISSN 0021-8561. 

In recent years, TLC was successfully combined with different ionization techniques, matrix-assisted laser desorption/ionization (MALDI), ESI, atmospheric pressure chemical ionization (APCI), desorption electrospray ionization (DESI), electrospray-assisted laser desorption ionization (ELDI), and LDI for identification and quantification of organic and biomolecules. In this section, the interfacing of TLC techniques with MALDI-ESI/MS, DESI-MS, ELSI-MS, and LDI-MS will be described, performance will be discussed, and selected applications in the separation and identification of lipids, gangliosides, dyes, drugs, and medicinal compounds will be presented. 

TABLE 15.1 TLC Combined with MALDI-MS Techniques for Identification of Lipids, Gangliosides, Drugs, and Other Organic Compounds O O 3 3 ... 

With all these more or less specific interactions shown by gangliosides, the question may be raised as to the involvement and the role played in those events by the two heterophilic molecular moieties of the glycolipid. VJe therefore chose two bacterial toxins, tetanus toxin and cholera toxin, to perform binding studies which were aimed at a further identification of the nature of the protein fixation by the sialo-glycolipid. 

This chapter has examined the more important aspects of qualitative and quantitative TLC of lipids, particularly as related to the various classes of neutral lipids, phosphoglycerides, glycoltptds, and gangliosides. Most attention has been paid to the separation and identification of lipids at the class level. Although some work on the analysis of the molecular species of lipids is available (46), TLC is not a primary method for such analyses. Moleeular species analysis has not been considered herein. 

Extensive studies on the chemical structure of the Tay-Sachs ganglioside have not shown a significant abnormality. As mentioned earlier, a compound with identical structure has been found among brain gangliosides of normal subjects. However, the sensitivity of these complex molecules toward treatment with alkali or acid, the possibility of spontaneous hydrolysis during handling and the complicated methods of structural identification render definite clarification of this point difficult. 

Low JA, Magnuson B, Tsai B, Imperiale MJ (2006) Identification of gangliosides GDlb and GTlb as receptors for BK virus. J Virol 80 1361-1366... 

Alternative methods of sialic acid determination have been described, but remain largely unused due to their poor sensitivity or difficulty in application relative to the assays described in these sections. These include the sulpho/phospho/vanillin method, originally used with gangliosides (Saifer and Feldman 1971), and the 1,10-phenanthroline method of Dimitrov (1973), which was subsequently refuted as a valid method by Snyder et al (1974). Of the remaining methods, already detailed at the beginning of section II, only the direct Ehrlich reaction has occasionally been employed where great sensitivity was of secondary importance (Werner and Odin 1952, Onodera et al 1965), or in cases where an additional colorimetric assay for identification of sialic acid was required (Onodera et al 1965, Cabezas 1973, Schauer 1978). 

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