Antioxidant Activities of Trypsin Inhibitor, a 33 KDa Root Storage Protein of Sweet Potato (Ipomoea batatas (L.) Lam cv. Tainong 57)

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• 作者：Wen-Chi Hou ; Yen-Chou Chen ; Hsien-Jung Chen ; Yaw-Huei Lin ; Ling-Ling Yang ; and Mei-Hsien Lee
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：2001
• 出版时间：June 2001
• 年：2001
• 卷：49
• 期：6
• 页码：2978 - 2981
• 全文大小：55K
• 年卷期：v.49,no.6(June 2001)
• ISSN：1520-5118

文摘

Trypsin inhibitors (TIs), root storage proteins, were purified from sweet potato (Ipomoea batatas[L.] Lam cv. Tainong 57) roots by trypsin affinity column according to the methods of Hou and Lin(Plant Sci. 1997, 126, 11-19 and Plant Sci. 1997, 128, 151-158). A single band of 33 kDa TI wasobtained by preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE)gels. This purified 33 kDa TI had scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH)radical. There was positive correlation between scavenging effects against DPPH (2 to 22%) andamounts of 33 kDa TI (1.92 to 46 pmol). The scavenging activities of 33 kDa TI against DPPH werecalculated from linear regression to be about one-third of those of glutathione between 5 and 80pmol. Using electron paramagnetic resonance (EPR) spectrometry for hydroxyl radical detection, itwas found that 33 kDa TI could capture hydroxyl radical, and the intensities of EPR signal weresignificantly decreased from 1.5 to 6 pmol of 33 kDa TI compared to those of the controls. It issuggested that 33 kDa TI, one of the sweet potato root storage proteins, may play a role as anantioxidant in roots and may be beneficial to health when it is consumed.Keywords: Antioxidant; electron paramagnetic resonance; hydroxyl radical; sweet potato; trypsininhibitor