Abstract:

A comparative investigation of the effects of material pretreatment ways and extraction solvents on protein extraction from Ginkgo biloba seeds was made, and based on the experimental results Tris-HCl as the optimal extraction solvent and lyophilization as the optimal material pretreatment way were selected for the subsequent investigations, including optimization of protein extraction from Ginkgo biloba seeds by single-factor and orthogonal array design methods and SDS-PAGE analysis of the proteins extracted from Ginkgo biloba seeds. The optimal conditions for extracting proteins from this material were determined to be: pH, 8.5; Tris-HCl concentration, 0.15 mol/L; material/liquid ratio, 1:20; and extraction duration, 4 h. A protein yield of 75.01% was obtained under the optimal extraction conditions. The SDS-PAGE analysis showed that the proteins from Ginkgo biloba seeds contained approximately 13 subunits (mainly 21 kD and 32 kD ones) and that majority of them had a molecular mass varying from 31 to 100 kD, with a relative content of 77%.

Key words: Ginkgo biloba seed, protein, extraction, SDS-PAGE