聚醚砜表面光固定脲酶的研究

我们利用含芳香叠氮基的光活性酯将脲酶光固定在聚醚砚（Polyether sulfone,PES）膜的表面。同时研究了紫外光辐照时间对固定化脲酶密度、固定化脲酶活性的影响，温度、PH值对自由脲酶、固定化脲酶相对活性的影响；并考察了固定化脲酶的相对活性随光活性酶浓度的变化、固定化脲酶的重复使用次数及储存稳定性等性质。结果表明，PES膜表面固定化脲酶的浓度为0.33mg/cm^2；当紫外光辐照时间为5分钟时，固定化脲酶的相对活性最高；固定化脲酶的最适Ph值和最适温度分别为7℃和50 ℃；在50℃时，连续使用12次后，固定化脲酶仍具有50%的催化活性；在4℃保存储存一个多月仍可保持80%的催化活性。

The Study of Photochemical Immobilization of Urease on Polyether Sulfone Film Surface

A new method of using photoactivable ester with azido group was described to immobilize urease on polyether sulfone(PES) film surface. The effects of photoactive enzyme concentration, temperature, pH, irradiation time on the activity of immobilized urease were investigated. Reused times and storage stability were also studied. The results showed that the surface concentration of urease immobilized on PES surface was about 0.33 mg/cm2. When the irradiation time was 5 minutes, the relative activity of immobilized urease was the highest and the activity increased with the increase of the concentration of photoactive urease solution. The optimum pH and temperature of immobilized urease were 7 and 50 degrees C respectively. The relative activity of immobilized urease was stable (50%) after 12 times reused at 50 degrees C.