摘要
以氯乙酰化聚苯乙烯树脂接枝四乙烯五胺、聚乙二醇链,用于固载α-淀粉酶,研究了酶的固定化条件和固定化对酶催化性能的影响。结果表明,PS-TEPA树脂对α-淀粉酶的吸附率达83%酶活和72%蛋白;PS-g-PEG树脂的吸附率达60%酶活和56%蛋白。使用戊二醛未能进一步提高酶的固定化量。酶在固定化后对底物的亲和力增加,vm ax/Km值从0.024（自由酶）上升至0.035（PS-TEPA）和0.038（PS-g-PEG）,最适反应温度从40℃（自由酶）上升为50℃（PS-TEPA）和60℃（PS-g-PEG）,最适反应pH值范围从7~8（自由酶）分别拓宽为7~10（PS-TEPA）和5~8（PS-g-PEG）。PS-TEPA树脂固定化酶经去离子水洗脱43 h后的残余相对酶活是717型树脂固定化酶的1.28倍,是PS树脂固定化酶的1.69倍。酶的失活半衰期在固定化后显著延长,70℃下的t1/2从1 h（自由酶）延长至4.5 h（PS-TEPA）和7.5 h（PS-g-PEG）。
Chloroacetylated polystyrene resin was grafted with tetraethylenepentamine or polyethylene glycol which was used to immobilize a-amylase. The immobilization process and the influence of immobilization on the catalytic characteristics of the a-amylase was investigated. It was found that the adsorption of a-amylase by PS-TEPA reached 83% （enzyme activity） and 72% （protein）, and the adsorption by PS-g-PEG was 60% （enzyme activity） and 56% （protein）. The use of glutaraldehyde had no positive effect on the immobilization of a-amylase. Compared to the free enzyme, the immobilized enzyme exhibited a higher affinity for the substrates, the value of Vmax/Km increased from 0. 024 （ free enzyme） to 0. 035 （PS-TEPA） and 0. 038 （ PS-g- PEG）, the optimum temperature was raised from 40℃ （free enzyme） to 50 ℃（PS-TEPA） and 60℃ （ PS-g- PEG）. The optimum pH range was also widened, from pH 7 -8（free enzyme） to pH 7 ~ 10（PS-TEPA） and pH 5 ~ 8 （PS-g-PEG） respectively. After washing with deionized water for 43 h, the residual adsorption of the enzyme on PS-TEPA was 1.28 times higher than that on 717 type resin, 1.69 times higher than that on IX3. The half life of α-amylase, t1/2, was prolonged after the immobilization, from 1 h（free enzyme） to 4. 5 h（PS- TEPA） and 7.5 h（PS-g-PEG） at 70 ℃.
出处
《应用化学》
CAS
CSCD
北大核心
2008年第11期1259-1265,共7页
Chinese Journal of Applied Chemistry
基金
国家高技术研究发展计划("八六三"计划2006AA10Z335)资助项目
