Characterization of soy β-conglycinin-dextran conjugate prepared by Maillard reaction in crowded liquid system

The conjugation reaction between soy β-conglycinin and dextran via Maillard reaction in crowded liquid system was studied. Apparent viscosity indicated that environment became more and more crowded with the increase of dextran concentration. The covalently linked conjugate was produced by incubating aqueous solution containing soy β-conglycinin and dextran at pH 7.0 and 95 °C for 6 h.Free amino group content and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) profile showed that soy β-conglycinin-dextran conjugate was successfully formed and macromolecular crowding enhanced the extent of glycation. The results of atomic force microscopy indicated that glycation inhibited the thermal aggregate of protein. Meanwhile, the tertiary structure of protein in conjugate changed with increasing number of aromatic side-chains exposed in heating environment. All data showed that the introduction of macromolecular crowding in soy β-conglycinin-dextran conjugate was an effective and promising method for linking polysaccharides to proteins.

► β-Conglycinin-dextran conjugate was successfully prepared in crowded liquid system. ► Macromolecular crowding environment prompted glycated reaction. ► Glycation increased protein solubility property near protein isoelectric point. ► In macromolecular crowding environment, glycation reduced protein aggregation. ► Glycation changed the tertiary structure of protein in crowding environment.