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

The conjugation reaction between soy beta-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 beta-conglycinin and dextran at pH 7.0 and 95 degrees C for 6 h. Free amino group content and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) profile showed that soy beta-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 beta-conglycinin-dextran conjugate was an effective and promising method for linking polysaccharides to proteins. (C) 2012 Elsevier Ltd. All rights reserved.