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

J Am Chem Soc. 2016 Feb 24;138(7):2130-3. doi: 10.1021/jacs.5b13180. Epub 2016 Feb 11.

Abstract

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.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Electron Transport
  • Imides / chemistry
  • Models, Molecular
  • Molecular Structure
  • Naphthalenes / chemistry
  • Organometallic Compounds / chemistry
  • Photochemical Processes*
  • Proteins / chemistry*
  • Zinc / chemistry

Substances

  • Imides
  • Naphthalenes
  • Organometallic Compounds
  • Proteins
  • naphthalenediimide
  • Zinc