Anti-GAL (full length) polyclonal antibody

N-glycans on the cell surface provide distinct signatures that are recognized by different glycan-binding proteins (GBPs) and pathogens. Most glycans in humans are asymmetric and isomeric, yet their biological functions are not well understood due to their lack of availability for studies. In this work, we have developed an improved strategy for asymmetric N-glycan assembly and diversification using designed common core substrates prepared chemically for selective enzymatic fucosylation and sialylation. The resulting 26 well-defined glycans that carry the sialic acid residue on different antennae were used in a microarray as a representative application to profile the binding specificity of hemagglutinin (HA) from the avian influenza virus (H5N2). We found distinct binding affinity for the Neu5Ac-Gal epitope linked to the N-acetylglucosamine (GlcNAc) of different branches and only a minor effect in binding for the terminal galactose on different branches. Overall, the microarray analysis showed branch-biased and context-based recognition patterns.

Mulberry leaves contain iminosugars, such as 1-deoxynojirimycin (1-DNJ), fagomine, and 2-O-alpha-D-galactopyranosyl deoxynojirimycin (GAL-DNJ) that inhibit alpha-glucosidase. In this study, we quantified iminosugars inMorus australisleaves and made the kinetic analysis in the hydrolysis of maltose by alpha-glucosidase. By LC-MS/MS, the concentrations of 1-DNJ, fagomine, and GAL-DNJ in the powdered leaves were 4.0, 0.46, and 2.5 mg/g, respectively, and those in the roasted ones were 1.0, 0.24, and 0.73 mg/g, respectively, suggesting that the roasting process degraded iminosugars. Steady-state kinetic analysis revealed that the powdered and roasted leaves exhibited competitive inhibition. At pH 6.0 at 37oC, the IC(50)values of the extracts from the boiled powdered or roasted leaves were 0.36 and 1.1 mg/mL, respectively. At the same condition, the IC(50)values of 1-DNJ, fagomine, and GAL-DNJ were 0.70 mu g/mL, 0.18 mg/mL, and 2.9 mg/mL, respectively. These results suggested that inM. australis, 1-DNJ is a major inhibitor of alpha-glucosidase.