Active Recombinant Thioredoxin h Protein with Antioxidant Activities from Sweet Potato (Ipomoea batatas [L.] Lam Tainong 57) Storage Roots

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• 作者：Dong-Jiann Huang ; Hsien-Jung Chen ; Wen-chi Hou ; Chun-Der Lin ; and Yaw-Huei Lin
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：2004
• 出版时间：July 28, 2004
• 年：2004
• 卷：52
• 期：15
• 页码：4720 - 4724
• 全文大小：85K
• 年卷期：v.52,no.15(July 28, 2004)
• ISSN：1520-5118

文摘

Recombinant thioredoxin h (Trx2) overproduced in Escherichia coli (M15) was purified by Ni²⁺-chelatedaffinity chromatography. The molecular mass of Trx2 is ~1.4 kDa as determined by sodium dodecylsulfate-polyacrylamide gel electrophoresis. Total antioxidant status, 1,1-diphenyl-2-picrylhydrazyl(DPPH) staining, reducing power method, Fe²⁺-chelating ability, ferric thiocyanate (FTC) method,and protection of calf thymus DNA against hydroxyl radical-induced damage were studied. Thethioredoxin h protein with a concentration of 12.5 mg/mL exhibited the highest activity (expressed as0.37 ± 0.012 mM ABTS radical cation being cleared) in a total antioxidant status test. In the DPPHstaining thioredoxin h appeared as white spots when it was diluted to 50 mg/mL (a final amount of15 g). Like the total antioxidant status, the reducing power, Fe²⁺-chelating ability, FTC activity, andprotection against hydroxyl radical-induced calf thymus DNA damage were found with the thioredoxinh protein. It was suggested that thioredoxin h might contribute to its antioxidant activities againsthydroxyl and peroxyl radicals.Keywords: Sweet potato; thioredoxin h; cDNA sequence; gene expression; recombinant protein;antioxidant