Improved activity of immobilized horseradish peroxidase on gold nanoparticles in the presence of bovine serum albumin
Improved activity of immobilized horseradish peroxidase on gold nanoparticles in the presence of bovine serum albumin
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DOI：
10.1007/s11051-013-2038-y
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发表时间：
2013-10
影响因子：
2.5
通讯作者：
Yuyang Ni;Jun Li;Zhenzhen Huang;Ke He;Jiaqi Zhuang;Wensheng Yang
中科院分区：
文献类型：
--
作者：
Yuyang Ni;Jun Li;Zhenzhen Huang;Ke He;Jiaqi Zhuang;Wensheng Yang
使用高分子添加剂是提高固定化酶活性的一种简单有效的方法，但其作用机理尚不清楚。以辣根过氧化物酶（HRP）为例，将其固定在25-nm的Au纳米颗粒表面后，其催化活性仅保持了30%，主要归因于含血红素的活性位点的构象变化。在固定化初期加入一定量的牛血清白蛋白（BSA），可使HRP的催化活性显著提高到80%。系统的光谱研究表明，BSA的加入抑制了酶活性中心附近的三级结构变化，这是提高固定化HRP活性的前提。稳态动力学分析表明，BSA的引入虽然降低了对底物的亲和力，但能有效提高底物转化率，从而提高了催化活性.
The using of macromolecular additives is known to be a simple and effective way to improve the activity of immobilized enzymes on solid support, yet the mechanism has not been well understood. Taking horseradish peroxidase (HRP) as an example, only 30 % of its catalytic activity was kept after being immobilized on the surface of 25-nm Au nanoparticles, mainly attributed to the conformational change of the heme-containing active site. The catalytic activity of HRP was significantly improved to 80 % when a certain amount of bovine serum albumin (BSA) was added at the initial stage of the immobilization. Systematic spectral investigation indicated that the addition of BSA inhibited the tertiary structure change around the active site, which was a prerequisite for improved activity of the immobilized HRP. Steady-state kinetic analyses revealed that the introduction of BSA could effectively improve the turnover rate of substrate to product in spite of slight reduced affinity to substrates, which also contributed to the improved catalytic activity.