食品科学 ›› 2008, Vol. 29 ›› Issue (3): 87-93.

• 基础研究 • 上一篇    下一篇

脂肪氧合酶催化亚油酸氧化与大豆蛋白相互作用过程中自由基迁移的电子顺磁共振研究(I)自由基的检测

 黄友如, 华欲飞, 顾建华, 王雪峰, 陈义勇   

  1. 常熟理工学院生物与食品工程系; 江南大学食品学院; 常熟理工学院生物与食品工程系 江苏常熟215500; 江苏无锡214036; 江苏常熟215500;
  • 出版日期:2008-03-15 发布日期:2011-08-24

Electron Paramagnetic Resonance Spectroscopy(EPR) Study on Free Radical Transfer in Lipoxygenase I-B-Catalyzing Linoleic Acid-soybean Protein Interaction(I) Detection of Free Radicals

 HUANG  You-Ru, HUA  Yu-Fei, GU  Jian-Hua, WANG  Xue-Feng, CHEN  Yi-Yong   

  1. 1.Department of Biological Science and Food Engineering, Changshu Institute of Technology, Changshu 215500, China; 2.School of Food Science and Engineering, Jiangnan University, Wuxi 214036, China
  • Online:2008-03-15 Published:2011-08-24

摘要: 应用电子顺磁共振(EPR)波谱研究了模拟体系中导致大豆蛋白聚集体形成的自由基由氧化亚油酸到大豆蛋白的迁移。经脂肪氧合酶催化亚油酸的诱导,在大豆蛋白EPR波谱中检测到一个很强的源于肽链骨架α-碳原子或其侧链其它碳原子的自由基信号,其g值范围在2.0041~2.0054之间。此外,在碳自由基中场信号的低场区尚有一个额外的肩峰,它是硫自由基信号,其g值范围在2.019~2.028之间。在大豆蛋白与脂肪氧合酶和亚油酸混合反应前,添加天然抗氧化剂如VC和α-生育酚或人工合成的抗氧化剂2,6-二叔丁基对甲酚(BHT)均能抑制自由基信号和荧光的发展,可使中场碳自由基信号降低35%~65%。

关键词: 大豆蛋白, 脂肪氧合酶, 亚油酸, 自由基, 电子顺磁共振

Abstract: Effects of lipoxygenase I-B (LOX) catalyzing oxidation of linoleic acid on soybean proteins were evaluated by electron paramagnetic resonance (EPR) spectroscopy in different model systems in the presence or absence of antioxidants. A strong central singlet signal was detected by EPR spectroscopy and identified as the carbon radical (g value range 2.0041 to 2.0054). A downfield shoulder attributed to the sulphur radical (g value 2.019 to 2.028) was also observed. Natural antioxidants such as ascorbic acid and α-tocopherol as well as synthetic antioxidants butyl hydroxytoluene (BHT) inhibited the development of the free radical signal when added to soybean proteins prior to incubation with linoleic acid and lipoxygenase I-B; the central singlet signal attributed to the carbon radical was reduced by 35%~65%.

Key words: soybean protein, lipoxygenase, linoleic acid, free radicals, EPR