This study validated the use of small unilamellar vesicles (SUVs) made of 1-palmitoyl-2-oleoylphosphatidylcholine with 1 mol % 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 (159 mmHg). 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.

中文翻译：

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具有 T 1 敏感饱和恢复 EPR 显示器的自旋标记小单层囊泡作为氧敏感分析物，用于测量细胞呼吸

本研究验证了使用由 1-棕榈酰-2-油酰磷脂酰胆碱制成的小单层囊泡 (SUV) 和 1 mol % 的 1-棕榈酰-2-(16-硬脂酰) 磷脂酰胆碱 (16-PC) 的自旋标记物作为氧敏感性用于研究细胞呼吸的分析物。在分析物中，烃环境围绕着 16-PC 的氮氧化物部分。这确保了氮氧化物位置处的高氧浓度和氧扩散，以及将氮氧化物部分与可能干扰自旋标记血氧饱和度测量的细胞还原剂和顺磁性离子隔离。饱和-恢复电子顺磁共振方法用于分析，因为这种方法是进行血氧饱和度研究的最直接方法。结果表明，该显示（自旋-晶格弛豫率）在氧气分压高达 100% 空气（159 mmHg）时呈线性。使用悬浮神经元细胞系的实验在 X 波段进行，用于封闭室几何形状。耗氧率与细胞数量呈线性关系。分析物的其他显着优点是：自旋探针的快速有效旋转扩散和缓慢平移扩散有利于测量，并且脂质双层中的氧和顺磁性离子之间没有交叉反应。