Analysis of Spin Label Line Shapes with Novel Inhomogeneous Broadening from Different Component Widths Application to Spatially Disconnected Domains in Membranes

Fluorescence quenching and electron spin resonance study of percolation in a two-phase lipid bilayer containing bacteriorhodopsin

“…5 and 8). It is also consistent with recent spectral simulations which suggest that the maximum in the spin-label concentration dependence of R will be too small to be detected, with the present precision of measurement, for domains that contain more than 500 lipid molecules (Sankaram and Marsh, 1996). The spin-label ESR measurements, like the fluorescence quenching experiments, therefore indicate that incorporation of BR increases the size and/or decreases the ramifications of the fluid domains in DMPC/DSPC mixtures, and concomitantly lowers the fluid lipid fraction at which connectivity of these domains is achieved.…”

EPR at work: Part 1

“…39, 44, and 45 showed the community how to use the effect of motion on the line shapes of spin labels to monitor the uncoiling of a protein, the binding of a nitrophenyl group to an antibody, and changes in membrane structure and dynamics upon other species interacting with the membrane. Spin label and spin probe studies have become major fields, encompassing fundamental studies of molecular motion (33), detailed structure of membranes (33)(34)(35)(36)(37), distance measurements (38), fundamental studies of electron spin relaxation in small molecules (39), and many other biomolecular problems. Special attention should be paid to the power of site-directed spin labeling, by which a spin label can be put at a selected position in a protein (36,40).…”

A new insight into a problem of mediating effects of humic acids on binding and biological effects of organic pollutants in natural soil

“…Close consideration has been taken to binding site of the aromatic amines and its peculiarities. The study has been based on the same effect of spectral anisotropy of label nitroxide group that has not been revealed when it has been tumbling rapidly and isotropically, whereas its covalent binding has evoked pronounced anisotropy of hyperfine splitting with respect to the magnetic field direction, and thus, a complex broadened EPR spectrum has been observed (Sankaram and Marsh 1998;Berliner 1998;Aleksandrova 2014). …”

“…I n e a r l i e r w o r k s (Aleksandrova et al 2011;Aleksandrova 2013), an effect of the specific functionality of contaminants was found using nitroxide spin labels with different substitutes, such as 4-Amino-TEMPO, 4-Hydroxy-TEMPO, and TEMPO, that were applied to luvisol and cambisol. Binding of organic chemicals to soil via the aromatic amine to luvisol and chernozem was considered in Aleksandrova et al (2013) and Aleksandrova (2014), using analyses of inhomogeneous broadening of EPR spectra of SL incubated with soil samples (Sankaram and Marsh 1998).…”