【摘要】 对-重氮基苯磺酰乙基琼脂糖是制备固定化多核苷酸磷酸化酶的较好材料,与具有同样活性基团的纤维素和葡聚糖凝胶G200相比,活力回收高、稳定性好。固定化酶的最适pH向偏碱的方向转移,最适温度较自然酶为宽,表观米氏常数与自然酶基本一致。57℃保温30分钟尚保留70%以上的活力,而自然酶仅剩余22%的活力,说明稳定性有所提高。更多还原

【Abstract】 Polynucleotide phosphorylase (PNPase) from E. Coli 1.183 was coupled to diazotized p-aminobenzenesulphonylethyl (ABSE) agarose. Its aotivity recovery and stability were superior to those of PNPase immobilized on ABSE-Sephadex G-200 and ABSE-cellulose.Upon immobilization, the optimum pH for the polymerization shifted from 9.6 to 10. The free enzyme showed maximum activity at 47℃, whereas the optimum temperature of the immobilized enzyme became rather broad, between 42~52℃. The apparent K_m of the immobilized enzyme was same as the free enzyme. The immobilized enzyme appeared to be more heat stable than the free enzyme. After treatment at 57℃ for 30 min, the retained activity of the immobilized enzyme was 72% while that of the free enzyme was 22%.更多还原