Renaturation of Lyophilized Concanavalin a Treated in Water Content Controlled Hydrated Ionic Liquids

A fraction of commercially available lyophilized concanavalin A (ConA) shows low mannose binding activity. In this study, we investigated the effects of the component ion and water content of hydrated ionic liquids (ILs) as treatment solvent on the mannose binding ability of lyophilized ConA. While high mannose binding ability was observed treated in hydrated ILs composed of dihydrogen phosphate anion with three water molecules per ion pair, it decreased with increase in water content. In contrast, no increase in mannose binding ability was observed after treatment with hydrated ILs composed of bromide anions. A steady response in mannose binding was observed after treatment with hydrated cholinium dihydrogen phosphate ([ch][dhp]). Following treatment with hydrated [ch][dhp] with three water molecules per ion pair, the mannose binding ability of lyophilized ConA increased twofold, while the low and high mannose binding ConA fraction showed an increase of 3.3 and 1.8 in the binding response, respectively.