Functional properties of glycoside synthesized using polyphenolic extract of Moringa oleifera catalyzed through transglycosylation reaction

The present study was designed to investigate gallic acid-4-O-β-glucopyranoside (GAGP) in normal and alloxaninduced diabetic rats by a single dose administration of alloxan (150 mg/kg, i.p.). Blood glucose levels measured weresignificantly (p < 0.05) increasing in all diabetic rats as compared with normal control rats. Three different dosagesof GAGP (100, 200, and 400 mg/kg, body weight) showed significantly decreasing (p < 0.05) blood glucose levelsof the diabetic rats (<3%) as compared with untreated diabetic group (>66%). All the hyperglycemic groups whichwere treated with various dosages of GAGP recorded lower biochemical parameters of blood serum as compared withuntreated diabetic group. A significant reduction in catalase activity (<40%–60%) of the diabetic groups was observedas compared with control group, while the diabetic groups showed elevation as compared with untreated diabeticgroup and catalase activity was quite near to normal rats. Glutathione levels of the diabetic groups were reduced(<2%–3%) but diabetic treated groups with different dosage showed improvement near to normal rats. In diabeticrat tissue, significant elevation (>45%) in lipid peroxidation was observed as compared with normal rats. In contrast,treatment with GAGP restores back near towards normal level (>5%–15%).

Glycosylation engineering of therapeutic IgG antibodies: challenges for the safety, functionality and efficacy

Glycosylation of the Fc region of IgG has a profound impact on the safety and clinical efficacy of therapeutic antibodies. While the biantennary complex-type oligosaccharide attached to Asn297 of the Fc is essential for antibody effector functions, fucose and outer-arm sugars attached to the core heptasaccharide that generate structural heterogeneity (glycoforms) exhibit unique biological activities. Hence, efficient and quantitative glycan analysis techniques have been increasingly important for the development and quality control of therapeutic antibodies, and glycan profiles of the Fc are recognized as critical quality attributes. In the past decade our understanding of the influence of glycosylation on the structure/function of IgG-Fc has grown rapidly through X-ray crystallographic and nuclear magnetic resonance studies, which provides possibilities for the design of novel antibody therapeutics. Furthermore, the chemoenzymatic glycoengineering approach using endoglycosidase-based glycosynthases may facilitate the development of homogeneous IgG glycoforms with desirable functionality as next-generation therapeutic antibodies. Thus, the Fc glycans are fertile ground for the improvement of the safety, functionality, and efficacy of therapeutic IgG antibodies in the era of precision medicine.

Purification and characterization of beta-glucosidase from Melanocarpus sp. MTCC 3922

This study reports the purification and characterization of beta-glucosidase from a newly isolated thermophilic fungus, Melanocarpus sp. Microbial Type Culture Collection (MTCC) 3922. The molecular weight of beta-glucosidase was determined to be ~ 92 and 102 kDa with SDS PAGE and gel filtration, respectively, and pI of ~ 4.1. It was optimally active at 60 C and pH 6.0, though was stable at 50 C and pH 5.0 - 6.0. The presence of DTT, mercaptoethanol and metal ions such as Na+, K+, Ca2+, Mg2+and Zn2+ positively influenced the activity of beta-glucosidase but the activity was inhibited in the presence of CuSO4. beta-Glucosidase recognized pNP- beta-glucopyranoside (pNPG) as the preferred substrate, and showed very low affinity for pNP- beta-D-cellobioside. Km and Vmax for the hydrolysis of pNPG by beta-glucosidase was calculated as 3.3 mM and 43.68 ‘molmin-1mg protein-1, respectively and k cat was quantified as 4 x 10³ min-1. beta-Glucosidase activity was enhanced appreciably in the presence of alcohols (methanol and ethanol) moreover, purified beta-glucosidase showed putative transglycosylation activity that was positively catalyzed in presence of methanol as an acceptor molecule