After opening a new class of chemical reactions in 1964, reactions in which unpaired
electrons of stable radicals were not involved, nitroxide (aminoxyl) radicals became
one of the most interesting and rapidly developing area of modern physical chemistry
with their application to biophysics, molecular biology, polymer sciences and
medicine. Further development of this field depends on new pathways in the nitroxide
chemistry, modern methods in EPR spectroscopy and revealing new perspective
EPR spectroscopy, performed after site-directed spin-labeling, was used to
study structural dynamics in a cold-adapted alkaline phosphatase (EC
220.127.116.11). Differences in the structural environment of six spin-labeled side
chains allowed them to be classified (with reference to previously obtained
mobility maps) as belonging to loop positions (either relatively surface
exposed or in structural contact) or helix positions (surface exposed, in
contact, or buried).
Conventional and saturation transfer electron paramagnetic resonance spectroscopy (EPR and ST EPR) was used to study the orientation of probe molecules in muscle ﬁbers in diﬀerent intermediate states of the ATP hydrolysis cycle. A separate procedure was used to obtain ST EPR spectra with precise phase settings even in the case of samples with low spectral intensity. Fibers prepared from rabbit psoas muscle were labeled with isothiocyanate spin labels at the reactive thiol sites of the catalytic domain of myosin....
bR, N-like and O-like intermediate states of [
type and D85N⁄T170C bacteriorhodopsin were accumulated in native
membranes by controlling the pH of the preparations.
N cross polariza-tion and magic angle sample spinning (CPMAS) NMR spectroscopy
allowed resolution of seven out of nine resonances in the bR-state. It was
possible to assign some of the observed resonances by using