Biochemistry Department, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia.
Int J Biol Macromol. 2013 Sep;60:295-300. doi: 10.1016/j.ijbiomac.2013.06.003. Epub 2013 Jun 12.
Recently, horseradish peroxidase (HRP) was immobilized on activated wool and we envisioned that the use of chitosan would be interesting instead of wool owing to its simple chemical structure, abundant nature and biodegradability. In this work, HRP was immobilized on chitosan crosslinked with cyanuric chloride. FT-IR spectroscopy and scanning electron microscopy were used to characterize immobilized HRP. The number of ten reuses of immobilized HRP has been detected. The pH was shifted from 5.5 for soluble HRP to 5.0 for immobilized enzyme. The soluble HRP had an optimum temperature of 30 °C, which was shifted to 35 °C for immobilized enzyme. The soluble HRP and immobilized HRP were thermal stable up to 35 and 45 °C, respectively. The apparent kinetic constant values (K(m)) of soluble HRP and chitosan-HRP were 35 mM and 40 mM for guaiacol and 2.73 mM and 5.7 mM for H2O2, respectively. Immobilization of HRP partially protected them from metal ions compared to soluble enzyme. The chitosan-HRP was remarkably more stable against urea, Triton X-100 and organic solvents. Chitosan-HRP exhibited large number of reuses and more resistance to harmful compounds compared with wool-HRP. On the basis of results obtained in the present study, chitosan-HRP could be employed in bioremediation application.
最近，辣根过氧化物酶（HRP）被固定在活化羊毛上，我们设想由于壳聚糖具有简单的化学结构、丰富的天然来源和生物降解性，使用壳聚糖而不是羊毛会很有趣。在这项工作中，HRP 被交联氰尿酰氯的壳聚糖固定化。傅里叶变换红外光谱和扫描电子显微镜用于表征固定化 HRP。已经检测到固定化 HRP 的 10 次重复使用次数。与可溶性 HRP 相比，固定化酶的 pH 值从 5.5 转移到 5.0。可溶性 HRP 的最适温度为 30°C，而固定化酶的最适温度为 35°C。可溶性 HRP 和固定化 HRP 的热稳定性分别高达 35°C 和 45°C。与壳聚糖-HRP 相比，可溶性 HRP 和壳聚糖-HRP 的表观动力学常数（K(m)）值分别为 35 mM 和 40 mM 用于愈创木酚，2.73 mM 和 5.7 mM 用于 H2O2。与可溶性酶相比，HRP 的固定化部分保护它们免受金属离子的影响。与羊毛-HRP 相比，壳聚糖-HRP 对尿素、Triton X-100 和有机溶剂更稳定。与羊毛-HRP 相比，壳聚糖-HRP 具有更多的重复使用次数和对有害化合物的更高抗性。根据本研究获得的结果，壳聚糖-HRP 可用于生物修复应用。
