title: Purification and characterization of a novel ~18 kDa antioxidant protein from Ginkgo biloba seeds.
abstract: Ginkgo biloba seeds are widely used as a food and traditional medicine in China. In the present study, a novel antioxidant protein named GBSP was purified from Ginkgo biloba seeds. The protein (GBSP) was purified by homogenization of Ginkgo biloba seed powder in saline solution, 70% ammonium sulphate precipitation, filtration on a DEAE-Cellulose52 anion exchange column, gel filtration on a Sephadex G-50 column, and preparative chromatography on a C(18) column using RP-HPLC. GBSP showed an apparent molecular weight of 18 kDa by SDS-PAGE and MALDI-TOF/MS analyses. The amino acid sequence obtained by MALDI-TOF/TOF MS analysis showed GBSP was a novel protein, as no matching protein in was found the database. The protein exhibited significant antioxidant activities against free radicals such as DPPH, ABTS and superoxide anion and showed higher activity than α-tocopherol in a linoleic acid emulsion assay system. Furthermore, GBSP exhibited notable reducing power and a strong chelating effect on Cu(2+) and Fe(2+). Therefore, the present study demonstrates, for the first time, that this novel protein from Ginkgo biloba seeds is an excellent antioxidant.
authors.affiliation: Institute of Chemical Industry of Forest Products, CAF, Nanjing 210042, Jiangsu, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Zhou
authors.forename: Xijuan
authors.initials: X
authors.lastname: Chen
authors.forename: Chengzhang
authors.initials: C
authors.lastname: Wang
authors.forename: Jianzhong
authors.initials: J
authors.lastname: Ye
authors.forename: Hongxia
authors.initials: H
authors.lastname: Chen
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D052160:Benzothiazoles / Q000494:pharmacology; D001713:Biphenyl Compounds / Q000494:pharmacology; D002681:China; D004591:Electrophoresis, Polyacrylamide Gel; D004655:Emulsions / Q000737:chemistry; D020441:Ginkgo biloba / Q000737:chemistry*; D019787:Linoleic Acid / Q000037:antagonists & inhibitors / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D010851:Picrates / Q000494:pharmacology; D010940:Plant Proteins / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D012639:Seeds / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013451:Sulfonic Acids / Q000494:pharmacology; D013481:Superoxides / Q000494:pharmacology; D024502:alpha-Tocopherol / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: D000975:Antioxidants; D052160:Benzothiazoles; D001713:Biphenyl Compounds; D004655:Emulsions; D010851:Picrates; D010940:Plant Proteins; D013451:Sulfonic Acids; D013481:Superoxides; C002502:2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid; D019787:Linoleic Acid; C004931:1,1-diphenyl-2-picrylhydrazyl; D024502:alpha-Tocopherol