化工学报 ›› 2013, Vol. 64 ›› Issue (6): 2160-2168.DOI: 10.3969/j.issn.0438-1157.2013.06.035

• 生物化学工程与技术 • 上一篇    下一篇

介孔TiO2晶须材料的硅烷化改性及其对载体pzc值和酶负载性能的影响

叶丽静, 房鑫, 王浩绮, 姚忠, 熊强, 周治, 孙芸, 韦萍   

  1. 南京工业大学食品与轻工学院,江苏 南京210009
  • 收稿日期:2012-10-11 修回日期:2013-03-05 出版日期:2013-06-05 发布日期:2013-06-05
  • 通讯作者: 姚忠
  • 作者简介:叶丽静(1988—),女,硕士研究生。
  • 基金资助:

    江苏省高校自然科学研究重大基金项目(10KJA530014);江苏省科技支撑计划(社会发展)基金项目(SBE 201078182);江苏省自然科学基金项目(BK2011799,BK2012825)。

Effect of surface modification with silane coupling agent on enhancing pzc value and enzyme loading capacity of mesoporous TiO2 whiskers

YE Lijing, FANG Xin, WANG Haoqi, YAO Zhong, XIONG Qiang, ZHOU Zhi, SUN Yun, WEI Ping   

  1. School of Food Science and Light Industry, Nanjing University of Technology, Nanjing 210009, Jiangsu, China
  • Received:2012-10-11 Revised:2013-03-05 Online:2013-06-05 Published:2013-06-05

摘要: 以3-氨丙基三乙氧基硅烷(APTES)对介孔二氧化钛晶须(MTiO2_ws)进行表面修饰,使其电荷零点值(pzc)由5.3提高至6.8,改性后材料MTiO2_ws-APTES的比表面积略有上升,但孔结构基本不变。以MTiO2_ws-APTES为载体对γ-谷氨酰转肽酶(GGT)进行了固定化,当给酶量小于150 U·g-1时,酶活回收率均大于99%,固定化酶MTiO2_ws-APTES-GGT的比活力最高可达184.0 U·g-1,对酶的负载性能显著优于MTiO2_ws。相比于游离酶,MTiO2_ws-APTES-GGT的最适温度和热稳定性均略有下降,但pH稳定性明显优于游离酶和以MTiO2_ws为载体的固定化酶(MTiO2_ws-GGT); MTiO2_ws-APTES-GGT对γ-谷氨酰对硝基苯胺(GpNA)的亲和力常数(Km)为0.889 mmol·L-1,较游离酶有所上升,但小于MTiO2_ws-GGT。MTiO2_ws-APTES-GGT的稳定性良好,经4℃下储藏60 d,连续使用21批次后残余酶活仍可达初始值的80.07%。

关键词: 介孔氧化钛晶须, 化学改性, 3-氨丙基三乙氧基硅烷, 固定化酶, 稳定性, 担载量

Abstract: Mesoporous TiO2 whiskers (MTiO2_ws) were chemically modified with 3-aminopropyltriethyloxy silane (APTES).As a result, the point of zero charge (pzc) for the modified material (MTiO2_ws-APTES) rose from 5.3 to 6.8.Also the specific surface area of MTiO2_ws-APTES slightly increased, but the pore structure had little change compared to that of MTiO2_ws.Then, MTiO2_ws-APTES was used as the support for γ-glutamyltranspeptidase (GGT) immobilization.MTiO2_ws-APTES showed better loading capacity than MTiO2_ws.While the enzyme concentration was less than 150 U·g-1, the recovery of activity was above 99% and the highest specific activity for immobilized GGT (MTiO2_ws-APTES-GGT) was 184.0 U·g-1.Although both optimal temperature and thermal stability of MTiO2_ ws-APTES-GGT slightly decreased compared with the native enzyme, pH stability was greatly improved.The affinity constant (Km) of MTiO2_ws-APTES-GGT toward γ-glutamyl-p-nitroaniline (GpNA) was also determined to be 0.889 mmol·L-1, which was higher than that of the native enzyme, but less than that of MTiO2_ws-GGT.After storage at 4℃ for 60 days and reused for 21 batches, MTiO2_ws-APTES-GGT maintained 80.07% of its initial activity.

Key words: mesoporous TiO2 whiskers, chemical modification, 3-aminopropyltriethyloxy silane, enzyme immobilization, stability, loading capacity

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