Abstract:

7S and 11S proteins were extracted from six representative soybean varieties, and purified with Superdex 200
gel column chromatography to a purity more than 90% as determined by using sodium dodecyl sulfate polyacrylamide
gel electrophoresis (SDS-PAGE). The secondary structures of 7S and 11S proteins were analyzed with Fourier transform
infrared spectroscopy. The surface hydrophobicities of 7S and 11S proteins were determined with 1-anilinonaphthalene-8-
sulfonic acid (ANS) fluorescence probe method. The structure-activity relationship was discussed with correlation analysis.
It was concluded that the surface hydrophobicity of the soybean proteins was negatively related to alpha helix content and
beta folding content but was positively correlated with beta angle content and random curl content.

Key words: 7S and 11S protein, secondary structure, Fourier transform infrared spectroscopy, surface hydrophobicity, correlation