Orientation selection in distance measurements between nitroxide spin labels at 94 GHz EPR with variable dual frequency irradiation

Phys Chem Chem Phys. 2013 Mar 14;15(10):3433-7. doi: 10.1039/c3cp44415e. Epub 2013 Feb 4.

Abstract

Pulsed electron-electron double resonance (PELDOR, also known as DEER) has become a method of choice to measure distances in biomolecules. In this work we show how the performance of the method can be improved at high EPR frequencies (94 GHz) using variable dual frequency irradiation in a dual mode cavity in order to obtain enhanced resolution toward orientation selection. Dipolar evolution traces of a representative RNA duplex and an α-helical peptide were analysed in terms of possible bi-radical structures by considering the inherent ambiguity of symmetry-related solutions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Molecular Structure
  • Nitrogen Oxides / chemistry*
  • Oligonucleotides / chemistry
  • Oligonucleotides / genetics
  • Peptides / chemistry
  • Peptides / genetics
  • Spin Labels*

Substances

  • Nitrogen Oxides
  • Oligonucleotides
  • Peptides
  • Spin Labels
  • r(GGCGBrUGCGCU)2
  • nitroxyl