Electron-Transfer Across Artificial Beta-Sheets

9307791 Ogawa州立鲍灵格林大学的Ogawa教授将在无机、生物无机和有机金属化学项目的支持下，研究人造β -褶片之间的电子转移。他将合成基于寡肽的化合物；这些将在末端成对连接，以诱导β -褶片构象。电子转移的供体和受体位点将附着在这些有帽的寡肽上，这样就可以评估β折叠片在介导电子转移中的作用。这些分子将通过圆二色性和多核磁共振光谱进行表征，并在可能的情况下通过x射线衍射进行表征。电子转移将由闪光光解引起，并由荧光和吸收光谱监测。主要目标将是确定β -褶纸是否像理论上预测的那样，在介导电子转移方面异常有效。电子通过蛋白质的转移是许多生命过程的重要组成部分。通常，这必须在原子尺度上经过很长的距离才能发生。有人认为，蛋白质中的某些结构基序在促进这种远距离电子转移事件方面特别有效。特别是，被称为“β -褶板”的结构已被牵连。为了验证这一假设，将通过设计和合成人造β -褶纸进行实验；这些分子将由能够参与电子转移反应的位点构成。然后测量电子转移的速率，并将其与缺少β -褶层的类似分子进行比较。所获得的信息将完善我们对蛋白质发挥其功能的方式的理解。＊＊＊

9307791 Ogawa Professor Ogawa of Bowling Green State University will investigate electron transfer across artificial beta-pleated sheets with support from the Inorganic, Bioinorganic, and Organometallic Chemistry Program. He will synthesize compounds based on oligopeptides; these will be joined in pairs at the ends so as to induce the beta-pleated sheet conformation. Electron transfer donor and acceptor sites will be attached to these capped oligopeptides so that the role of beta pleated sheets in mediating electron transfer can be assessed. The molecules will be characterized by circular dichroism and multinuclear nmr spectroscopy, and where possible by x-ray diffraction. Electron transfer will be initiated by flash photolysis and monitored by fluorescence and absorption spectroscopy. The primary goal will be to determine if beta-pleated sheets are unusually effective in mediating electron transfer, as has been predicted theoretically. %%% The transfer of an electron through proteins is an essential component of many life processes. Often this must occur through distances that are long on the atomic scale. It has been suggested that certain structural motifs within proteins are especially effective in fostering such long range electron transfer events. In particular, structures known as "beta-pleated sheets" have been implicated. Experiments to test this hypothesis will be conducted by designing and synthesizing artificial beta-pleated sheets; these molecules will be constructed with sites that are able to participate in electron transfer reactions. The rates of electron transfer will then be measured and compared with those of similar molecules that lack the beta-pleated sheets. The information to be obtained will refine our understanding of the ways that proteins perform their functions. ***