CETE, -CH2CH2SCH2CH2COOMe, is a linkage (spacer) arm, and CETE glycosides may be amidically linked creating a stable, uncharged linkage to amino groups in proteins or to solid phases (a description of coupling method is available).

In general, CETE-glycosides are ideal for preparation of neoglycoproteins or neoglycolipids, for covalent coupling to other molecules and for covalent binding to solid phases, such as for example separation materials or biosensor surfaces (Nilsson and Mandenius, in Bio/Technology, 12, 1994, p. 1376-1378).

The CETE glycoside consists of the sugar plus the CETE spacer which is ß -linked to the sugar. Thus, Sugarß-O-Ch2CH2-S-CH2CH2-COOMe. These glycosides are slightly hydrophilic and maybe used for analysis of e.g. galactosyl-transferases using e.g. TLC plates or HPLC for quantification of activity. To couple these glycosides to amino-groups on proteins, peptides or other amino-group containing compounds, as well as aminogroup containing ELISA-plates or other surfaces, you have to either remove the Me group under slightly basic conditions, and form the COOH group and couple via EDC or other recommended procedure by NUNC, or you can activate the COOMe group via conversion first to the hydrazide and then to the acyl azide. The conversion to the acyl azide is a straightforward procedure and is easily done in the lab using a ventilated hood. The acyl azide can then be reacted with amino groups. Guideline for a disaccharide-CETE glycoside using conversion to acyl acide: 100 mg (or 0,2 mmol) of the glycoside is dissolved in 1,5 ml of 96 % ethanol and mixed with 0,2 ml of 85 % hydrazine in water. Stir at room temperature over night and evaporate to dryness. This gives the hydrazide (i.e. the -COOMe group is converted to -CO-NHNH2). This compound is stable. Conversion to acyl azide and general guide-line for coupling: Dissolve the hydrazide (7,35 mg) in 200 microl DMSO and treat with 4 M HCl in 1,4-dioxane (50 microliter) and tert-butyl-nitrite (5 microliter) in methyl sulphoxide (25 microliter). The mixture is stirred at room temperature for 30 minutes, a solution of sulphamic acid (2,5 mg) in methylsulphoxide (25 microliter) is added, and after 15 min, the mixture is added with stirring to cool coupling buffer pH 7-9 containing the protein (7-10 mg) recommended by NUNC, check pH. It is possible that you have to check the pH during coupling the first times you do these reactions (change buffer strength) and that you will optimize the procedure (amount of sugar, coupling time) for coupling to an ELISA plate, the same procedure might be used, but then the acyl acid mixture is added to cool (4 degrees Celsius)coupling buffer(without protein) and added to e.g the ELISA plate (e.g. NUNC-plates containing aminogroups.

The list of conjugates below will be modified and extended upon customer demand. If you are interested in other types of glycosides for covalent coupling, please contact us.

As mentioned above, one of our specialities is large scale synthesis.Therefore, if you are interested in larger quantities or custom synthesis, please contact us.

Special characters:
ß = beta
á = alpha