Site-Directed Spin-Labeling ESR-Structural Analysis on the Supramolecular Protein Complex during Biological Activity-

Membrane Protein Structure and Dynamics Studied by Site-directed Spin Labeling Esr

Attaching a spin to a protein -- site-directed spin labeling in structural biology.

Site-directed spin labeling and electron paramagnetic resonance spectroscopy have recently experienced an outburst of multiple applications in protein science. Numerous interesting strategies have been introduced for determining the structure of proteins and its conformational changes at the level of the backbone fold. Moreover, considerable technical development in the field makes the techniqu...

Site-directed Spin Labeling of the Mitochondrial Membrane

NCCD (N-(2,2,6,6-tetramethyl-piperidyl-l-oxyl)-N’-(cyclohexyl)carbodiimide) is a spin label inhibitor of ATPase of mitochondrial membrane fragments. Upon binding (~0.5 nmole per mg of protein) its electron paramagnetic resonance spectrum becomes highly immobilized (7, = 2.10m8 s). The bound but not the free label is reduced by succinate, indicating that electrons can be transferred from the res...

Noncovalent and site-directed spin labeling of nucleic acids.

Electron paramagnetic resonance (EPR) spectroscopy is widely used to study free radicals or paramagnetic centers associated with biopolymers. With the advent of pulsed EPR methods, which allow accurate distance measurements between 20 and 80 , structures of biopolymers have increasingly been interrogated by this technique. Some of the advantages of EPR spectroscopy over other structural techniq...

Noncovalent and site-directed spin labeling of duplex RNA.

An isoindoline-nitroxide derivative of guanine (Ǵ, "G-spin") was shown to bind specifically and effectively to abasic sites in duplex RNAs. Distance measurements on a Ǵ-labeled duplex RNA with PELDOR (DEER) showed a strong orientation dependence. Thus, Ǵ is a readily synthesized, orientation-selective spin label for "mix and measure" PELDOR experiments.