Asialofetuin, immobilized

After immobilization the grafted surfaces were probed by lection recognition and cell activity tests. Data were correlated with analytical data from XPS and ToF-SIMS. Alio A lectin binding was performed on y -sterilized ELISA plates. The wells were modified with different concentration of MAD-Gal. Inhibition tests were performed on surfaces modified with 0.25 mM solution of MASD-Gal and asialofetuin (1 mg/ml) as an inhibitor. Figure 4 summarizes the results. 

The fraction eluted in the void volume is dialyzed against 10 mM phosphate buffer, pH 6.8, with 0.145 M NaCl and passed successively over two columns, of immobilized lactose and asialofetuin (1 mg bRT/1 mL gel) equilibrated with the abovementioned phosphate buffer. 

Fig. 20. Binding of biotinylated Alio A lectin to MAD-Gal derivatized PS surface. The deriva tized PS surfaces were incubated with Alio A lectin and then extensively washed to remove physisorbed lectins. [ S] streptavidin was added and the surfaces were again washed to re move excess streptavidin. Finally, radioactivity was measured by scintillation counting. The radioactivity is higher on sample C and increases with the concentration of the MAD-Gal so lution (C, Cl and C2 corresponding to 0.25, 0.025 and 0.0025 mmol/1. respectively) used for immobilization. This illustrates the higher binding of streptavidin to the surface C. I corre spends to incubation of MAD-Gal grafted PS with asialofetuin and Alio A lectin. 100% corresponds to the total added radioactive streptavidin after [105]...

Dendrimers up to a G3 generation (octavalent) were synthesized based on the 3,5-di-(2-aminoethoxy)-benzoic acid branching unit and tested in an SPR competition assay with immobilized asialofetuin. Strong multivalency effects were observed, up to a factor of 4t)0, which reached the Hmit of the assay [47]. Even more spectacular enhancements were obtained with a divalent ligand, prepared by tethering two units of 42 onto a functionalized caHx[4]arene. A 3800-fold (1900-fold per sugar mimic) affinity eiihancement was measured by fluorescence spectroscopy, thus reaching the same potency of GMl-os [59]. 

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