摘要
研究了尿酸酶分离纯化条件和pH、温度、底物浓度、一些有机和无机试剂对尿酸酶酶促反应速度的影响．研究结果表明，用Triton X-100及巯基乙醇处理细胞悬液（pH8．5），再用超声波处理破碎细胞效果最佳．硫酸铵沉淀尿酸酶的最佳浓度为75％．用Phenyl-Sepharose CL-4B疏水层析和Xamhine-agarose亲和层析两步纯化步骤可获得理想纯度的酶制剂．在一定的条件下，尿酸酶的最适pH和酸破稳定pH范围分别为8．5和5．0～12．最适温度为37℃；热稳定性较好，在50℃处理30min时活性保持90％，在60℃处理30min时活性仍保持80％．在最适条件下，该酶催化尿酸的米氏常数（Km）为3．34×10^-5mol／L．一些金属离子和有机化合物对酶活性的影响也进行了研究．
The purification condition of uricase and the effects of pH, temperature, substrate concentration, some organic and inorganic compounds on the enzyme activity were studied. According to the research results, it was best method to treat the cell suspending （pH 8.5） with ultrasonic fragmentation followed by Triton X- 100 and mercaptoethanol. 75% ammonium sulfate fractionation can get the most uriease activity field, Through the two-step purification procedure, including Phenyl-Sepharose CL-4B chromatography and Xanthine-agarose affinity chromatography, it can be obtained enzyme preparation with high purity. On the stated condition, the optimum pH and range of pH stability were 8.5 and 5.0-12.0. The enzyme showed good thermal stability with 37＊Cas its optimum temperature, The enzyme activity remained 90% when treated in 50℃ for 30 minutes and also remains 80 % in 60℃ for 30 minutes. The Km of purified uricase was 3.34 × 10^-5 mol/L at pH 8.5 and 40℃. Also, the effects of some metal ions and organic compounds on the enzyme activity were studied.
出处
《四川大学学报（自然科学版）》
CAS
CSCD
北大核心
2006年第2期414-419,共6页
Journal of Sichuan University(Natural Science Edition)
基金
国家科技部技术创新资助项目(04C26225120848)
关键词
尿酸酶
产朊圆酵母
动力学特性
Uricase
Torula utilis Hermeb
dynamic characteristics
