Structures and functions of reaction spaces constructed using metalloprotiens

去年，我们为X射线晶体结构研究捕获ap-ferritin的内部表面的氨基酸溶液指定了负责人。在补充中，我们审查了Au 3 + ions的居住地，并发现了一些Au离子绑定站点，在apo-ferritin中与那些具有不同协调国家结构的Pd有不同的区别。在这些观测的基础上，我们准备了两种类型的金属纳米簇，我.....。Alloy and Core/shell在Schem 1中展示在共同减量中， Au和Pd在apo-ferritin笼中共存。笼子中每个离子的数量是由每个离子对特定氨基酸居住者的亲和力调节的。顺便说一下，合金纳米粒子由133个Au原子和165个Pd原子（（AuPd）·apo-ferritin）组成。在另一方面，我们成功地准备好了Au核/Pd壳（[Au] （Pd））和Pd核/Au壳（[Pd] （Au））类型的纳米粒子，由201 Au原子/305 Pd原子和169 Au原子/65 Pd原子组成。在那些apo-ferritin复合物中， [Au] （Pd） apo-ferritin展示了烯烃氢化的最高催化活性。在一个单独的实验中，我们已经测试了一个有机化合物的可能成分，如[Pd（allyl）C1]2和[Rh（norbornadiene）C1]2在apo-ferritin中。Pd（异黄酮）的晶体结构·apo-ferritin清楚地显示了异黄酮群分子对apo-ferritin中的Pd离子的作用。

Last year, we have specified the amino acid residues responsible for capturing Pd2+ ions on the interior surface of ap-ferritin by X-ray crystal structural studies. In addition, we have examined the residues which ligate to Au3+ ions and found that some of the Au ion binding sites in apo-ferritin are different from those of Pd ions with different coordi-nation structures. On the basis of these observation, we have prepared two type of metal nano-clusters, i.e., alloy and core/shell as shown in Schem 1. In the co-reduction, Au and Pd ions coexist in the apo-ferritin cage. The number of each ion in the cage is regulated by the affinity of each ions to its specific amino acid residues. Consequently, the alloy nano-particle was composed of 133 Au atoms and 165 Pd atoms ((AuPd)・apo-ferritin). On the other hand, we have successfully prepared Au-core/Pd-shell([Au] (Pd)) and Pd-core/Au-shell ([Pd] (Au)) types of nano-particles composed of 201 Au atoms/305 Pd atoms and 169 Au atoms/65Pd atoms, respectively. Among those apo-ferritin composites, [Au] (Pd) apo-ferritin shows the highest catalytic activity for the hydrogenation of olefins.In a separate experiment, we have examined a possible incorporation of organometallic compounds such as [Pd(allyl)C1]2 and [Rh(norbornadiene)C1]2 in apo-ferritin. The crystal structure of Pd(allyl)・apo-ferritin clearly shows that the allyl group ligates to Pd ion in apo-ferritin.