Purification of Proteins from Ginkgo Biloba Seeds and Their Antioxidant Activities

Ginkgo biloba seeds were widely used for food and traditional medicine in china. In the present study, antioxidant proteins named GP were purified from Ginkgo biloba seeds. The proteins (GP) were purified by homogenization of Ginkgo biloba seeds powder in the saline solution, precipitation with 70% ammonium sulphate, and filtration on DEAE-Cellulose 52 anion exchange column. GP showed protein content of 96%, and they showed three bands with approximate molecular weight of 15 kDa, 17 kDa, 21 kDa respectively by SDS-PAGE electrophoresis analysis. Compositions of amino acids obtained by Amino Acid Analyzer showed GP were rich in Glu, Ser ,His ,Asp, Gly, Ala, Leu and Lys compared with the other fractions. The antioxidant activities of GP were investigated using DPPH (the 1, 1-diphenyl-2-picrylhydrazyl) free radical-scavenging and ferric-reducing antioxidant power assays. The GP showed antioxidant activities higher than α-Tocopherol and BHA. Therefore, the present study demonstrates proteins from Ginkgo biloba seeds (GP) can be excellent antioxidant.