Tourtellotte M E, Branton D, Keith A
Proc Natl Acad Sci U S A. 1970 Jul;66(3):909-16. doi: 10.1073/pnas.66.3.909.
A spin-labeled fatty acid was incorporated in vivo into the polar lipids of Mycoplasma laidlawii membranes. The electron paramagnetic resonance signal from either intact cells or their extracted lipids reflected the fatty acid composition of the Mycoplasma membranes. Comparison of signals from intact cells, gramicidin-treated cells, heat-treated cells, and extracted lipids indicates that a major portion of the membrane lipids is in a semiviscous hydrocarbon environment. The results also show that the spin label in the intact membrane is slightly but significantly less mobile than it is in protein-free lipid extracts made from these membranes. Correlated electron microscope examinations using the freeze-etch technique reveal particulate components in the hydrophobic region of the membrane. The mobility of the lipids in the intact cell membrane may be influenced by their association with these particles.
一种自旋标记脂肪酸在体内被掺入莱氏无胆甾原体细胞膜的极性脂质中。来自完整细胞或其提取脂质的电子顺磁共振信号反映了支原体膜的脂肪酸组成。对完整细胞、短杆菌肽处理细胞、热处理细胞和提取脂质的信号比较表明，膜脂质的主要部分处于半粘性烃环境中。结果还表明，完整膜中的自旋标记比从这些膜制备的无蛋白脂质提取物中的自旋标记移动性略低但显著降低。使用冷冻蚀刻技术的相关电子显微镜检查揭示了膜疏水区域中的颗粒成分。完整细胞膜中脂质的移动性可能受其与这些颗粒的缔合影响。
