Immobilization of alliinase with a water soluble–insoluble reversible N

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• 作者：Jian Qin Zhou ; Jian Wen Wang
• 关键词：N-Succinyl-chitosan ; Soluble– ; insoluble ; Immobilization ; Alliinase ; Alliin
• 刊名：Enzyme and Microbial Technology
• 出版年：2009
• 出版时间：7 October 2009
• 年：2009
• 卷：45
• 期：4
• 页码：299-304
• 全文大小：757 K

文摘

N-Succinyl-chitosan (NSC), a pH-sensitive polymer of reversibly soluble–insoluble characteristics with pH change, was prepared by modification of the chitosan backbone with succinic anhydride and employed as carrier for alliinase immobilization. The obtained NSC is soluble at pH above 4.8 and insoluble at pH below 4.4. The characteristics of NSC were evaluated using Fourier transform IR spectrophotometer, the X-ray diffraction spectrometry and thermogravimetric analyzer. Under an optimized condition (glutaraldehyde 0.8 % (v/v), 31.2 U alliinase), the enzyme immobilization yield was 75.6 % . The maximum activity of NSCA was achieved at 40 °C, pH 7, while the free enzyme exhibited maximum activity at 30 °C, pH 6. The Michaelis–Menten constant of NSCA was lower than that of free alliinase, indicating higher affinity of immobilized enzyme toward its substrate. The NSCA retained 85 % of its initial activity even after being recycled 5 times. The immobilized alliinase in reversibly soluble NSC is suitable to catalyze the conversion of alliin to allicin, as active ingredient of pharmaceutical compositions and food additive.