caa a22 4500 605545952 CHVBK 20210128100938.0 cr unu---uuuuu 210128e20150801xx s 000 0 eng 10.1007/s00723-015-0684-1 doi (NATIONALLICENCE)springer-10.1007/s00723-015-0684-1 Spin-Labeled Small Unilamellar Vesicles with the T 1-Sensitive Saturation-Recovery EPR Display as an Oxygen-Sensitive Analyte for Measurement of Cellular Respiration [Elektronische Daten] [Laxman Mainali, Jeannette Vasquez-Vivar, James Hyde, Witold Subczynski] This study validated the use of small unilamellar vesicles (SUVs) made of 1-palmitoyl-2-oleoylphosphatidylcholine with 1mol% spin label of 1-palmitoyl-2-(16-doxylstearoyl)phosphatidylcholine (16-PC) as an oxygen-sensitive analyte to study cellular respiration. In the analyte, the hydrocarbon environment surrounds the nitroxide moiety of 16-PC. This ensures high oxygen concentration and oxygen diffusion at the location of the nitroxide as well as isolation of the nitroxide moiety from cellular reductants and paramagnetic ions that might interfere with spin-label oximetry measurements. The saturation-recovery electron paramagnetic resonance approach was applied in the analysis since this approach is the most direct method to carry out oximetric studies. It was shown that this display (spin-lattice relaxation rate) is linear in oxygen partial pressure up to 100% air (159mmHg). Experiments using a neuronal cell line in suspension were carried out at X-band for closed-chamber geometry. Oxygen consumption rates showed a linear dependence on the number of cells. Other significant benefits of the analyte are: the fast effective rotational diffusion and slow translational diffusion of the spin-probe is favorable for the measurements, and there is no cross-reactivity between oxygen and paramagnetic ions in the lipid bilayer. Springer-Verlag Wien, 2015 Mainali Laxman Department of Biophysics, Medical College of Wisconsin, 8701 Watertown Plank Road, 53226, Milwaukee, WI, USA aut Vasquez-Vivar Jeannette Department of Biophysics, Medical College of Wisconsin, 8701 Watertown Plank Road, 53226, Milwaukee, WI, USA aut Hyde James Department of Biophysics, Medical College of Wisconsin, 8701 Watertown Plank Road, 53226, Milwaukee, WI, USA aut Subczynski Witold Department of Biophysics, Medical College of Wisconsin, 8701 Watertown Plank Road, 53226, Milwaukee, WI, USA aut Applied Magnetic Resonance Springer Vienna 46/8(2015-08-01), 885-895 0937-9347 46:8<885 2015 46 723 https://doi.org/10.1007/s00723-015-0684-1 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00723-015-0684-1 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Mainali Laxman Department of Biophysics, Medical College of Wisconsin, 8701 Watertown Plank Road, 53226, Milwaukee, WI, USA aut NATIONALLICENCE 700 1- Vasquez-Vivar Jeannette Department of Biophysics, Medical College of Wisconsin, 8701 Watertown Plank Road, 53226, Milwaukee, WI, USA aut NATIONALLICENCE 700 1- Hyde James Department of Biophysics, Medical College of Wisconsin, 8701 Watertown Plank Road, 53226, Milwaukee, WI, USA aut NATIONALLICENCE 700 1- Subczynski Witold Department of Biophysics, Medical College of Wisconsin, 8701 Watertown Plank Road, 53226, Milwaukee, WI, USA aut NATIONALLICENCE 773 0- Applied Magnetic Resonance Springer Vienna 46/8(2015-08-01), 885-895 0937-9347 46:8<885 2015 46 723