A Serum D-Fucose Binding Lectin With B Cell Mitogenic Activity From the Grub of the Darkling Beetle Zophobas morio

Lectins that can recognize and bind to carbohydrates and glycoconjugates are at the epicentre of research owing to their prospective applications. In the present study, a D-fucose binding lectin from the serum of darkling beetle, Zophobas morio was purified and their mitogenic potential over human B-cells was evaluated. Biochemical assays on the preliminary characterization revealed the occurrence of single D-fucose binding lectin. Through single step affinity chromatography using D-fucose coupled Epoxy-activated Sepharose 6B, lectin (ZmFBL) with a molecular mass of ~192 kDa from the serum of Z. morio was purified with homogeneity. The HA activity of the purified ZmFBL remained stable between the pH 7 and 12 and was thermo-tolerant up to a temperature of 40°C. MALDI-TOF-MS analysis of native lectin disclosed fucose-binding nature of the ZmFBL with mitogenic property. The results of functional analysis of purified ZmFBL on the effect on B-cell proliferation revealed that ZmFBL at the concentrations of 31.25 μg and 62.50 were the ideal concentrations that significantly enhanced (approximately 2.5-fold over control) the proliferation of the B-lymphocyte population up to 72 h of treatment without any cytotoxicity. The outcome of this study could possibly prove beneficial in the investigation on the potential use of ZmFBL as immunostimulant and in immunosuppressive treatments.