Protocol abstract

Nature Protocols 2, 1770 - 1781 (2007)
Published online: 12 July 2007 | doi:10.1038/nprot.2007.255

Subject Categories: Spectroscopy and structural analysis | Biochemistry and protein analysis

Measuring distances in proteins by saturation-recovery EPR

Donald J Hirsh1 & Gary W Brudvig2

We describe a protocol for detecting electron spin–spin interactions between a radical and a metal ion in a protein or protein complex by saturation-recovery electron paramagnetic resonance (EPR). This protocol can be used with a protein containing an endogenous metal center and either an endogenous or synthetic radical species. We suggest a two-step approach whereby dipole–dipole or exchange interactions are first detected by continuous-wave EPR experiments and then quantified by saturation-recovery EPR. The latter measurements make it possible to measure long distances to within a few Ångstroms. The protocol for making distance measurements by saturation-recovery EPR will take approximately 6 days to complete.

  1. Department of Chemistry, The College of New Jersey, PO Box 7718, Ewing, New Jersey 08628, USA.
  2. Department of Chemistry, Yale University, 225 Prospect Street, PO Box 208107, New Haven, Connecticut 06520, USA.

Correspondence to: Donald J Hirsh1 e-mail:


These links to content published by NPG are automatically generated.


Motion of muscle proteins

Nature News and Views (07 Aug 1975)

Nanoporous materials A selective magnetic sponge

Nature Materials News and Views (01 Mar 2003)

Nuclear antiferromagnetism

Nature News and Views (27 Apr 1978)

Biochemistry Radicals by reduction

Nature News and Views (13 Mar 2008)

See all 5 matches for News And Views