The use of ESR imaging for the rapid determination of diffusion coefficients, D, in anisotropic solvents is reported, and the use of Fourier transforms of the concentration profile to determine D is discussed. An approximate rapid analysis technique is also presented. The ditfusion coefficients for motion perpendicular to the director axis for 4-0x02,2,6,6,-tetramethylpiperidine-I-oxyl (TEMPONE...

ESR studies on spin-labeled amorphous RNase A as a function of varying concentrations of sorbed H2O and D2O will be presented. A relaxation analysis of saturation transfer (ST-)ESR spectra of 14N(1H) nitroxide spin-label molecules essentially fixed at amino acid residue His-105 will be given. A characteristic correlation has been observed between the microdynamic behavior--expressed by the rota...

the efficient detection of charged biomolecules by biosensor with appropriate semiconducting nanomaterials and with optimum device geometry has caught tremendous research interest in the present decade. here, the performance of various label-free electronic biosensors to detect bio-molecules is investigated by simulation technique. silicon nanowire sensor, nanosphere sensor and double gate fiel...

We present the performance of nanometer-range pulse electron paramagnetic resonance distance measurements (pulsed electron-electron double resonance/double electron-electron resonance, PELDOR/DEER) on a transmembrane WALP24 peptide labeled with the semirigid unnatural amino acid 4-(3,3,5,5-tetra-methyl-2,6-dioxo-4-oxylpiperazin-1-yl)-l-phenylglycine (TOPP). Distances reported by the TOPP label ...

There is now a great deal of physical and chemical evidence that horse and human hemoglobins undergo a change of protein conformation on oxygenation.' 9 The molecular mechanism whereby these hemoglobins show cooperative or sigmoidal oxygen binding has remained obscure, however. In order to understand this "heme-heme" interaction, one must obtain structural information on partially oxygenated he...

Rigid-limit 250-GHz electron spin resonance (FIR-ESR) spectra have been studied for a series of phosphatidylcholine spin labels (n-PC, where n = 5, 7, 10, 12, 16) in pure lipid dispersions of dipalmitoylphosphatidylcholine (DPPC) and 1-palmitoyl-2-oleoylphosphatidylcholine (POPC), as well as dispersions of DPPC containing the peptide gramicidin A (GA) in a 1:1 molar ratio. The enhanced g-tensor...

Electron paramagnetic resonance (EPR) was used to optimize the solid-phase peptide synthesis of a membrane-bound peptide labeled with TOAC (2,2,6,6-tetramethyl-piperidine-1-oxyl-4-amino-4-carboxylic acid). The incorporation of this paramagnetic amino acid results in a nitroxide spin label coupled rigidly to the alpha-carbon, providing direct detection of peptide backbone dynamics by EPR. We app...

The rotational motions of F-a&in filaments and myosin heads attached to them have been measured by saturation transfer electron paramagnetic resonance spectroscopy using spin-labels rigidly bound to actin, or to the myosin head region in intact myosin molecules, heavy meromyosin, and subfragment-1. The spin-label attached to F-actin undergoes rotational motion having an effective correlation ti...