Models of the ctiue sites of metalloproteins : synthetic, structural, and functional studies on metallopeptides

1)制备了汞肽[(Boc-Cys-Pro-Leu-Cys-Gly-Ala-OMe)Hg]，并通过EXAFS、ROESY、距离几何（DG）、约束分子动力学（RMD）计算，对其配位和构象结构进行了研究。与[(Boc-Cys-Pro-Leu-Cys-OMe)Hg]的结构比较表明，两者都具有镜像型γ -结构。2)我们用同样的方法澄清了[(Boc-Cys-Pro-Leu-Cys-OMe)(S-tert-C_4H_9)Hg]的结构。本研究阐明了Cys-X_2-Cys的构象不取决于金属离子的种类，而取决于S-M-S咬角，该化合物的肽构象与锌指基序的锌结合位点一致。我们合成了[(Boc-Cys-Pro-Leu-Cys-OMe)Zn]和[(boc - cys - pro - leu - cys - gly - al - ome)Zn]。我们研究了这些化合物的锌位的取代反应。通过分子轨道计算、MD计算、EXAFS、nmr对Boc-Glu-Thr-Ile-His-OMe与Zn^<2+>在蛋白酶锌结合位点上的络合物形成进行了研究。ROESY， RMD和MO的结构研究表明，该系统产生了一个与蛋白酶相应位点结构相似的物种。5)在模板辅助合成蛋白方法的基础上，以尖桩栅栏卟啉为模板，重新设计合成了一种能够将多种卟啉结合到其His位点的人工蛋白。该肽卟啉将另一种类型的卟啉结合到His位点，形成一系列三聚体聚集体，从而形成12杂卟啉体系。

1) We prepared the mercury peptide, [(Boc-Cys-Pro-Leu-Cys-Gly-Ala-OMe)Hg], and studied the coordination and conformation structures by EXAFS, ROESY, distance geometry (DG), restrained molecular dynamics (RMD) calculations, -. Comparison of the structure with that of [(Boc-Cys-Pro-Leu-Cys-OMe)Hg] revealed that both of these have a mirror type gamma-tum structure.2) We clarified the structure of [(Boc-Cys-Pro-Leu-Cys-OMe)(S-tert-C_4H_9)Hg] by the same way as above. This study clarified that the conformation of Cys-X_2-Cys does not depend on the kinds of metal ions, but depends on the S-M-S bite angle, and the peptide conformation obtained for this compound agreed with that of the zinc binding sites of zinc finger motifs3)We synthesized [(Boc-Cys-Pro-Leu-Cys-OMe)Zn] and [(Boc-Cys-Pro-Leu-Cys-Gly-Ala-OMe)Zn] in terms of zinc finger motifs. We studied the substitution reactions of the zinc sites of these compounds. The structure of the former was discussed by molecular orbital calculations, MD calculations, EXAFS, NMR.4) We studied the complex formation between Boc-Glu-Thr-Ile-His-OMe and Zn^<2+> with respect to the zinc binding sites of proteases. The structural study by ROESY, RMD and MO suggested that this system generates a species which is structurally similar to the corresponding sites of proteases.5) We de novo designed and synthesized an artificial protein, which is capable of incorporating multiple porphyrins into its His sites, on the basis of template assisted synthetic protein approach, where a picket fence porphyrin was adopted as the template. This peptide porphyrin incorporated another types of porphyrins into the His sites forming a series of trimeric aggregates, thus achieved a 12 hetero-porphyrin system.