Pulse EPR Measurements of Intramolecular Distances in a TOPP-Labeled Transmembrane Peptide in Lipids.

A combined pulse EPR and Monte Carlo simulation study provides molecular insight on peptide-membrane interactions.

We present a new approach to obtain details on the distribution and average structure and locations of membrane-associated peptides. The approach combines (i) pulse double electron-electron resonance (DEER) to determine intramolecular distances between residues in spin labeled peptides, (ii) electron spin echo envelope modulation (ESEEM) experiments to measure water exposure and the direct inte...

TOPP: a novel nitroxide-labeled amino acid for EPR distance measurements.

Multiple Locations of Peptides in the Hydrocarbon Core of Gel-Phase Membranes Revealed by Peptide C to Lipid H Rotational-Echo Double-Resonance Solid-State Nuclear Magnetic Resonance

Membrane locations of peptides and proteins are often critical to their functions. Solid-state rotational-echo double-resonance (REDOR) nuclear magnetic resonance is applied to probe the locations of two peptides via peptide CO to lipid H distance measurements. The peptides are KALP, an α-helical membrane-spanning peptide, and HFP, the β-sheet N-terminal fusion peptide of the HIV gp41 fusion pr...

Integration of a K+ channel-associated peptide in a lipid bilayer: conformation, lipid-protein interactions, and rotational diffusion.

The 26-residue peptide of sequence KEALYILMVLGFFGFFTLGIMLSYIR, which contains the single putative transmembrane domain of a small protein that is associated with slow voltage-gated K+ channels, has been incorporated in bilayers of dimyristoylphosphatidylcholine by dialysis from 2-chloroethanol to form complexes of homogeneous lipid/peptide ratio. Fourier transform infrared spectroscopy indicate...

High-resolution measurement of long-range distances in RNA: pulse EPR spectroscopy with TEMPO-labeled nucleotides

SI1: Sample characterization by HPLC and CW-EPR spectroscopy. Figure S1: (a) Anion exchange traces of purified single-stranded double-C T -labeled RNAs. (b) Spin concentration calibration curve. (c) RNA labelling efficiency. SI2: Examination of orientation selection. Figure S2: Highand low-power Q-band DEER on [13,28] RNA duplex. Figure S3: High-power Q-band DEER on different RNA samples. Figur...