Visible-light-induced activity control of peroxidase bound to Fe-doped titanate nanosheets with nanometric lateral dimensions
Visible-light-induced activity control of peroxidase bound to Fe-doped titanate nanosheets with nanometric lateral dimensions
复制标题
可见光诱导的过氧化物酶活性控制与纳米横向尺寸的铁掺杂钛酸盐纳米片结合
DOI：
10.1021/acs.bioconjchem.5b00464
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发表时间：
2015
影响因子：
4.7
通讯作者：
Nobuaki Soh
中科院分区：
文献类型：
--
作者：
Kai Kamada;Daiki Ito;Nobuaki Soh
在可见光照射下，成功地将辣根过氧化物酶(HRP)静电吸附在纳米级和半导体型掺铁钛酸盐(FT)纳米片上，研究了HRP的催化性能。通过金属源的水解反应，制备了一种具有窄禁带的FT胶体溶液，该溶液对应于可见光区域。在pH=4的条件下，HRP和FT之间通过静电作用可以很容易地结合到FT上，形成的HRP-FT被用于可见光驱动的酶反应。在具有足够能级的可见光照射下，HRP-FT的催化活性显著高于自由(非结合)HRP，且仅受光强的调节。此外，酶反应速率的波长依赖关系类似于FT的光学吸收光谱。这些结果证实了一种预期的反应机理，即光酶反应是由FT的带隙激发引发的，然后将辐照后的FT价带中产生的空穴转移到HRP。被激发的HRP氧化底物(Amplex紫外红：AuR)伴随着两个电子的还原来再生休眠状态。此外，通过打开和关闭光源，可以清楚地切换催化活性。
Catalytic performance of horseradish peroxidase (HRP) electrostatically adsorbed on nanometric and semiconducting Fe-doped titanate (FT) nanosheets was successfully manipulated by visible light illumination. A colloidal solution of FT with a narrow band gap corresponding to a visible light region was fabricated through a hydrolysis reaction of metals sources. HRP could be easily bound to the FT at pH = 4 through an electrostatic interaction between them, and the formed HRP-FT was utilized for the visible-light-driven enzymatic reaction. Under exposure to visible light with enough energy for band gap excitation of the FT, catalytic activity of HRP-FT was dramatically enhanced as compared with free (unbound) HRP and was simply adjusted by light intensity. In addition, wavelength dependence of an enzymatic reaction rate was analogous to an optical absorption spectrum of the FT. These results substantiated an expected reaction mechanism in which the photoenzymatic reaction was initiated by band gap excitation of FT followed by transferring holes generated in the valence band of irradiated FT to HRP. The excited HRP oxidized substrates (amplex ultrared: AUR) accompanied by two-electron reduction to regenerate the resting state. In addition, the catalytic activity was clearly switched by turning on and off the light source.