Mechanism of Accumulation and Incorporation of Organometallic Pd Complexes into the Protein Nanocage of apo-Ferritin
Mechanism of Accumulation and Incorporation of Organometallic Pd Complexes into the Protein Nanocage of apo-Ferritin
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DOI：
10.1021/ic1003758
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发表时间：
2010-08-02
影响因子：
4.6
通讯作者：
Ueno, Takafumi
中科院分区：
文献类型：
--
作者：
Abe, Satoshi;Hikage, Tatsuo;Ueno, Takafumi
金属配合物与蛋白质支架的杂交是生物无机化学和材料科学中的一个重要课题。为蛋白质提供非自然功能的努力可能会导致催化剂、传感器等的发展取得进展。对金属配合物在蛋白质支架内结合过程的机理研究以及所产生的配位结构的表征将有助于我们设计和控制金属配合物的配位结构，从而构建含金属配合物的杂交蛋白。在这项工作中，通过对载脂蛋白铁蛋白（apo-Fr）的x射线晶体结构及其选择突变体的分析，阐明了在金属配合物存在下，有机金属钯配合物在铁储存蛋白（apo-Fr）笼内的积累和结合过程。载子fr含Pd（烯丙基）（烯丙基= eta(3)-C3H5）配合物的晶体结构表明，在载子fr笼内的两个结合位点形成了硫代桥接的双核Pd（烯丙基）配合物。载子fr及其含有Pd（烯丙基）复合物的Cys-和his -缺失突变体的晶体结构表明，Cys126加速了Pd（烯丙基）复合物进入笼中的过程。此外，Cys48和Cys126对于Pd（烯丙基）配合物的积累和正方形平面配位结构的稳定至关重要。
Hybridization of metal complexes and protein scaffolds is an important subject in bioinorganic chemistry and materials science. Efforts to provide non-natural functions to proteins will likely lead to advances in development of catalysts, sensors, and so on. Mechanistic investigations of the process of binding of metal complexes within protein scaffolds and characterization of the resulting coordination structures will help us to design and control coordination structures of metal complexes for construction of hybrid proteins containing metal complexes. In this work, the processes of accumulation and incorporation of organometallic palladium complexes within the cage of the iron storage protein apo-ferritin (apo-Fr) are elucidated by analysis of X-ray crystal structures of apo-Fr and selected mutants thereof, in the presence of the metal complexes. The crystal structure of apo-Fr containing Pd(allyl) (allyl = eta(3)-C3H5) complexes shows that thiolato-bridged dinuclear Pd(allyl) complexes are formed at two binding sites within the cage of apo-Fr. The crystal structures of apo-Fr and its Cys- and His-deletion mutants containing Pd(allyl) complexes indicate that Cys126 accelerates the incorporation of Pd(allyl) complexes into the cage. In addition, Cys48 and Cys126 are essential for accumulation of Pd(allyl) complexes and stabilizing the square planar coordination structure.