Direct evidence of active-site reduction and photodriven catalysis in sensitized hydrogenase assemblies.
Direct evidence of active-site reduction and photodriven catalysis in sensitized hydrogenase assemblies.
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DOI：
10.1021/ja3042367
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发表时间：
2012-07-11
影响因子：
15
通讯作者：
Dyer, R. Brian
中科院分区：
文献类型：
--
作者：
Greene, Brandon L.;Joseph, Crisjoe A.;Maroney, Michael J.;Dyer, R. Brian
我们报道了氢化酶（H2 ase）-量子点（QD）杂化组装体光催化制氢。观察到CdTe激子发射的淬灭，与从量子点到H2酶的电子转移一致。GC分析显示在牺牲电子供体存在下光驱动的H2产生具有4%的效率，这可能是这些混合系统的下限。采用FTIR直接观察活性位点减少在前所未有的细节光驱动的H2酶催化对H2酶和牺牲电子供体的敏感性。用Ru（bpy）32+的光敏化显示出独特的FTIR光还原性质，产生沿着稳态催化循环的所有状态沿着最小的H2产生，表明缓慢的连续单电子还原步骤。比较两种体系的H2酶活性和FTIR结果表明，量子点更有效地结合电子转移和最终的酶状态是不同的两种敏化剂。这些差异的可能来源和它们的影响，酶的机制进行了讨论。
We report photo-catalytic H2 production by hydrogenase (H2ase)-quantum dot (QD) hybrid assemblies. Quenching of the CdTe exciton emission is observed, consistent with electron transfer from quantum dot to H2ase. GC analysis shows light driven H2 production in the presence of a sacrificial electron donor with an efficiency of 4%, which is likely a lower limit to these hybrid systems. FTIR was employed for direct observation of active site reduction in unprecedented detail for photo-driven H2ase catalysis with sensitivity towards both H2ase and sacrificial electron donor. Photosensitization with Ru(bpy)32+ shows distinct FTIR photo- reduction properties generating all states along the steady-state catalytic cycle with minimal H2 production indicating slow, sequential one electron reduction steps. Comparing H2ase activity and FTIR results of both systems shows that QDs bind more efficiently for electron transfer and the final enzyme state is different for the two sensitizers. The possible origins of these differences and their implications for the enzymatic mechanism are discussed.
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DOI：
10.1073/pnas.1100610108
发表时间：
2011-04-12
影响因子：
11.1
作者：
Pandelia, Maria-Eirini;Nitschke, Wolfgang;Lubitz, Wolfgang
通讯作者：
Lubitz, Wolfgang
DOI：
10.1098/rsta.2004.1528
发表时间：
2005-04-15
影响因子：
5
作者：
Armstrong, FA;Albracht, PJ
通讯作者：
Albracht, PJ
影响因子：
15
作者：
Madden, Christopher;Vaughn, Michael D.;Moore, Thomas A.
通讯作者：
Moore, Thomas A.
影响因子：
3
作者：
Bleijlevens, B;van Broekhuizen, FA;Albracht, SPJ
通讯作者：
Albracht, SPJ
影响因子：
15
作者：
WHITEHEAD, JP;GURBIEL, RJ;MARONEY, MJ
通讯作者：
MARONEY, MJ