The use of the Rx spin label in orientation measurement on proteins, by EPR.

The use of the Rx spin label in orientation measurement on proteins, by EPR† †Electronic supplementary information (ESI) available. See DOI: 10.1039/c5cp04753f Click here for additional data file.

Demystifying EPR: A Rookie Guide to the Application of Electron Paramagnetic Resonance Spectroscopy on Biomolecules

Electron Paramagnetic Resonance (EPR) spectroscopy, also known as Electron Spin Resonance(ESR) especially among physicists, is a strong and versatile spectroscopic method forinvestigation of paramagnetic systems, i.e. systems like free radicals and most transition metalions, which have unpaired electrons. The sensitivity and selectivity of EPR are notable andintriguing as compared to other spec...

Bifunctional Spin Labeling of Muscle Proteins: Accurate Rotational Dynamics, Orientation, and Distance by EPR.

While EPR allows for the characterization of protein structure and function due to its exquisite sensitivity to spin label dynamics, orientation, and distance, these measurements are often limited in sensitivity due to the use of labels that are attached via flexible monofunctional bonds, incurring additional disorder and nanosecond dynamics. In this chapter, we present methods for using a bifu...

Simulating the Distance Distribution between Spin-Labels Attached to Proteins

EPR/DEER spectroscopy is playing an increasingly important role in the characterization of the conformational states of proteins. In this study, force field parameters for the bifunctional spin-label (RX) used in EPR/DEER are parametrized and tested with molecular dynamics (MD) simulations. The dihedral angles connecting the Cα atom of the backbone to the nitroxide ring moiety of the RX spin-la...

Structure and dynamics of a conformationally constrained nitroxide side chain and applications in EPR spectroscopy.

A disulfide-linked nitroxide side chain (R1) is the most widely used spin label for determining protein topology, mapping structural changes, and characterizing nanosecond backbone motions by site-directed spin labeling. Although the internal motion of R1 and the number of preferred rotamers are limited, translating interspin distance measurements and spatial orientation information into struct...