Photoinduced Electron Transfer Elicits a Change in the Static Dielectric Constant of a de Novo Designed Protein

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• 作者：Nicholas F. Polizzi ; Matthew J. Eibling ; Jose Manuel Perez-Aguilar ; Jeff Rawson ; Christopher J. Lanci ; H. Christopher Fry ; David N. Beratan ; Jeffery G. Saven ; Michael J. Therien
• 刊名：Journal of the American Chemical Society
• 出版年：2016
• 出版时间：February 24, 2016
• 年：2016
• 卷：138
• 期：7
• 页码：2130-2133
• 全文大小：377K
• ISSN：1520-5126

文摘

We provide a direct measure of the change in effective dielectric constant (ε_S) within a protein matrix after a photoinduced electron transfer (ET) reaction. A linked donor–bridge–acceptor molecule, PZn–Ph–NDI, consisting of a (porphinato)Zn donor (PZn), a phenyl bridge (Ph), and a naphthalene diimide acceptor (NDI), is shown to be a “meter” to indicate protein dielectric environment. We calibrated PZn–Ph–NDI ET dynamics as a function of solvent dielectric, and computationally de novo designed a protein SCPZnI3 to bind PZn–Ph–NDI in its interior. Mapping the protein ET dynamics onto the calibrated ET catalogue shows that SCPZnI3 undergoes a switch in the effective dielectric constant following photoinduced ET, from ε_S ≈ 8 to ε_S ≈ 3.