The elderberry (Sambucus nigra L.) bark lectin recognizes the Neu5Ac(alpha 2-6)Gal/GalNAc sequence.
Carbohydrate binding properties of a new plant lectin isolated from elderberry (Sambucus nigra L.) (SNA) bark were studied using the techniques of quantitative precipitation, hapten inhibition, and equilibrium dialysis.Purified SNA precipitates highly sialylated glycoproteins such as fetuin, orosomu...
Uloženo v:
| Hlavní autoři: | , , , , , |
|---|---|
| Médium: | Artigo |
| Jazyk: | angličtina |
| Vydáno: |
1987
|
| On-line přístup: | https://doi.org/10.1016/s0021-9258(19)75677-4 |
| Tagy: |
Přidat tag
Žádné tagy, Buďte první, kdo vytvoří štítek k tomuto záznamu!
|
| Shrnutí: | Carbohydrate binding properties of a new plant lectin isolated from elderberry (Sambucus nigra L.) (SNA) bark were studied using the techniques of quantitative precipitation, hapten inhibition, and equilibrium dialysis.Purified SNA precipitates highly sialylated glycoproteins such as fetuin, orosomucoid, and ovine submaxillary mucin, but not their asialo derivatives.Hapten inhibition experiments showed that both D-Gal and D-GalNAc are weak inhibitors of SNA-glycophorin precipitation, but neither Neu5Ac nor Neu5Gc is an inhibitor.A series of oligosaccharides which contain the terminal Neu5Ac(a2-6)Gal sequence showed an extremely high inhibitory potency (1,600-10,000 times more inhibitory than Gal).On the other hand, oligosaccharides with the NeuSAc(a2-3)Gal linkage were only 30-80 times more inhibitory than Gal, thus showing a marked preference for the 2,6-linked isomer.Hapten inhibition with Gal and its epimers suggested that the equatorial OH at C-3 and the axial OH at C-4 of the D-pyranose ring are strict requirements for binding.Conversion of the yeu5Ac residue to its 7-carbon analogue by selective periodate oxidation of its glyceryl side chain, followed by NaBH, reduction, completely destroyed the ability of fetuin and orosomucoid to precipitate with SNA.Moreover, the same treatment of Neu5Ac(a2-3)lactitol also abolished its ability to inhibit the precipitation reaction, suggesting that the glyceryl side chain of Neu5Ac (especially the C-8 and/or C-9 portion) is an important determinant for SNA.The increased inhibitory potency of various glycosides with &linked ,nonpolar aglycons suggested the presence of a hydrophibic interacting region adjacent to the carbohydrate binding site.The results of equilibrium dialysis using [3H] Neu5Ac(a2-6)lactitol as ligand showed the presence of two equivalent, noninteracting carbohydrate binding sites in this tetrameric glycoprotein lectin (Km = 3.9 X 10' M-').Plant lectins have been widely used for the detection, isolation, and characterization of glycoconjugates using their characteristic carbohydrate binding properties.Although over 100 plant lectins have already been isolated and their carbohydrate binding specificity has been at least partially char- |
|---|