Peptide Models for Type III Copper Sites in Proteins

描述（由申请人提供）：本研究旨在检测三种肽中铜(I)和铜（ll）的结合位点，以建立金属离子的配位环境。在项目的第一阶段，将检查制备的多肽的溶液构象，在有无铜(I)和铜（ll）离子存在的情况下，以确定铜络合所必需的构象变化程度。利用EPR、ENDOR、ESEEM、NMR和FTIR进一步确定铜肽配合物中铜的结合位点。所制备的两种多肽将以2:1的铜(I)/肽比与适当的铜盐反应，以产生二铜络合物。通过与分子氧的反应，二铜配合物转化为二氧加合物。每个配体的二氧配合物将通过电子吸收光谱和核磁共振光谱进行研究。研究了二氧配合物对水和其他质子溶剂的稳定性。物理研究，包括x射线结构分析，建议对所有分离的氧或脱氧形式的配合物。

DESCRIPTION (provided by applicant): The proposed study involves examining the binding sites of copper (I) and copper (ll) in three peptides with a view to establishing the coordination environment of the metal ion. In the first stage of the project, the solution conformation of the prepared peptides will be examined with and without the presence of copper (I) and copper (ll) ions in order to establish the extent of conformational change that is necessary for complexation of copper. The binding sites of copper in the copper-peptide complexes will be further determined with EPR, ENDOR, ESEEM, NMR and FTIR spectroscopy. Two of the prepared peptides will be reacted with an appropriate copper salt in a 2:1 copper (I)/peptide ratio in order to produce a dicopper complex. The dicopper complex will be transformed into a dioxygen adduct through reaction with molecular oxygen. The dioxygen complex for each ligand will be investigated by the use of electronic absorption spectroscopy and NMR spectroscopy. Stability of the dioxygen complex towards water and other protic solvents will be examined. Physical studies, including X-ray structural analysis, are proposed for all isolated complexes of the oxy or deoxy forms.