Fucose, stability

The inverting GH 95 1,2-oc-L-fucosidase (EC 3.2.1.63) from Bifidobacterium bifi-dum in complex (PDB 2EAC) with 1-deoxy-L-fuconojirimycin (20) showed the inhibitor in C4 chair conformation, resembling L-fucose and the entrance to the active site was narrowed by the gate keeper loops.315 A calcium ion associated with the protein was not involved in the catalytic process but was considered to stabilize the enzyme. 

Experiment 3. Role of a-L-fucose in the Stability of Lectin-Glycoproteins Complexes... 

Albani, J.R., Debray, H., Vincent, M. and Gallay, J. (1997). Role of the carbohydrate moiety and of the alpha 1-fucose in the stabilization and the dynamics of the Lens culinaris agglutinin-glycoprotein complex. A fluorescence study. Journal of Fluorescence, 7, 293-298. 

It is believed that the apiofiiranose (Api residue of side chain A, but not that of side-chain B, is involved in RG-II dimerization. Recently mutant Arabidopsis murl strains, which are defective in L-fucose biosynthesis, have been shown to result in small changes in chain A of RG-II the L-fucose residue is replaced by L-galactose. This seemingly minor modification in a complex oligosaccharide structure results in a significant reduction in RG-II dimer formation and has a dramatic impact of plant morphology(/P). It is not yet clear which structural features of RG-II are key to borate ester formation and stability. 

Table 3.30 Stability of the response factors for fucose, galactosamine, and mannose as a function of the number of injections without postchromatographic column cleanup.

Human liver a-L-fucosidase has been separated into four components by gel filtration and ion-exchange chromatography. These components differed in their relative stabilities to heat and acid and in their response to neuraminidase. The enzymes were able to liberate L-fucose from 2 -L-fucosyl-lactose. The serum enzyme was also investigated. 

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