Development of a new EPR spin trap, DOD-8C (N-[4-dodecyloxy-2-(7′-carboxyhept-1′-yloxy)benzylidene]-N-tert-butylamine N-oxide), for the trapping of lipid radicals at a predetermined depth within biological membranes

2005 ◽  
Vol 435 (2) ◽  
pp. 336-346 ◽  
Author(s):  
Alison Hay ◽  
Mark J. Burkitt ◽  
Clare M. Jones ◽  
Richard C. Hartley
Author(s):  
S.W. Hui ◽  
D.F. Parsons

The development of the hydration stages for electron microscopes has opened up the application of electron diffraction in the study of biological membranes. Membrane specimen can now be observed without the artifacts introduced during drying, fixation and staining. The advantages of the electron diffraction technique, such as the abilities to observe small areas and thin specimens, to image and to screen impurities, to vary the camera length, and to reduce data collection time are fully utilized. Here we report our pioneering work in this area.


Author(s):  
Neng-Bo He ◽  
S.W. Hui

Monolayers and planar "black" lipid membranes have been widely used as models for studying the structure and properties of biological membranes. Because of the lack of a suitable method to prepare these membranes for electron microscopic observation, their ultrastructure is so far not well understood. A method of forming molecular bilayers over the holes of fine mesh grids was developed by Hui et al. to study hydrated and unsupported lipid bilayers by electron diffraction, and to image phase separated domains by diffraction contrast. We now adapted the method of Pattus et al. of spreading biological membranes vesicles on the air-water interfaces to reconstitute biological membranes into unsupported planar films for electron microscopic study. hemoglobin-free human erythrocyte membrane stroma was prepared by hemolysis. The membranes were spreaded at 20°C on balanced salt solution in a Langmuir trough until a surface pressure of 20 dyne/cm was reached. The surface film was repeatedly washed by passing to adjacent troughs over shallow partitions (fig. 1).


1997 ◽  
Vol 62 (6) ◽  
pp. 855-865 ◽  
Author(s):  
Katarína Erentová ◽  
Vladimír Adamčík ◽  
Andrej Staško ◽  
Oskar Nuyken ◽  
Arming Lang ◽  
...  

The cathodically and photochemically induced decomposition of thioazo compounds XC6H4-N2-S-C6H4CH3 and their polymers with X = NO2, COOH, and SO3H were investigated. The formation of carbon-centered XC6H4. and sulfur-centered .S-C6H4Y radicals was confirmed using spin-trap technique. These reactive radicals either abstract hydrogen from CH3CN solvent molecule forming .CH2CN radical or they recombine to cage products XC6H4-S-C6H4CH3 eliminating N2. The decomposition rate of the investigated thioazo compounds is characterized by a formal half-life time of 5 to 10 s.


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