食品科学 ›› 2008, Vol. 29 ›› Issue (9): 420-422.

• 生物工程 • 上一篇    下一篇

奶油黄嘌呤氧化酶的酶学性质研究

 李忠琴, 许小平, 王武   

  1. 江南大学工业生物技术教育部重点实验室; 福州大学化学化工学院;
  • 出版日期:2008-09-15 发布日期:2011-12-08

Study on Characteristics of Xanthine Oxidase from Milk Cream

 LI  Zhong-Qin, XU  Xiao-Ping, WANG  Wu   

  1. 1. Key Laboratory of Industry Biotechnology,Ministry of Education,Jiangnan University,Wuxi 214122,China; 2. College of Chemistry and Chemical Engineering,Fuzhou University,Fuzhou 350002,China
  • Online:2008-09-15 Published:2011-12-08

摘要: 利用反向高效液相色谱(RP-HPLC)测定该酶产物尿酸的生成量,研究黄嘌呤氧化酶的酶学特性。结果表明,在50mmol/LTris-HCl缓冲液和0.24mmol/L黄嘌呤的体系中,该酶检测反应的最适温度为37℃,最适pH8.4。XOD在pH7.0~9.0,40℃以下稳定,对黄嘌呤的Km值为0.043mmol/L。XOD酶激活剂包括水杨酸钠、半胱氨酸、组胺、硫酸铵、乙二胺四乙酸等。金属离子对其活性有抑制作用。低浓度表面活性剂Tween80、SDS和TritonX-100对该酶活力影响不明显。

关键词: 黄嘌呤氧化酶, 酶学特性, 稳定性

Abstract: This work aimed to study the characteristics of xanthine oxidase (XOD) by using RP-HPLC to determine formation amount of uric acid, the product by the enzyme. The results showed the optimal reaction pH and temperature of XOD in 50 mmol/L Tris-HCl buffer are 8.4 and 37 ℃, respectively. But the enzyme is still stable at the pH ranging from 7.0 to 9.0 and below 40 ℃. The Km value of this enzyme is calculated as being 0.043 mmol/L. Further experimental results revealed that XOD can be activated by sodium salicylate, cysteine, histamine, (NH4)2SO4 and EDTA, but be inhibited by some metal ions (especially Ag+ and Hg2+), urea, 6-aldehyde purine and 2-amino-4-hydroxypteridine 6-aldehyde. The activity of XOD is hardly affected by low concentration of surface-activator such as Tween 80, SDS and Triton X-100.

Key words: xanthine oxidase, enzymologic characteristics, stability