Yamauchi T, Ohki K, Maruyama H, Nozawa Y
Biochim Biophys Acta. 1981 Dec 7;649(2):385-92. doi: 10.1016/0005-2736(81)90428-4.
During temperature acclimation of Tetrahymena pyriformis, the changes in fluidity and composition of total lipids from three membrane fractions, mitochondria, pellicles and microsomes were studied by a spin-label technique using a stearate probe and thin-layer and gas-liquid chromatography. The increase of fluidity observed in microsomal and pellicular lipids following the temperature shift from 39 to 15 degrees C corresponds with the increase of the ratio of total unsaturated to saturated fatty acid content. However, despite the increase of this ratio, the fluidity of mitochondrial lipids was found to be constant up to 10 h after the temperature shift. The fluidity of total lipids of mitochondria isolated from Tetrahymena cells grown at 39 degrees C was not changed by removal of cardiolipin, whereas cardiolipin-depleted lipids of mitochondria from 15 degrees C-acclimated cells showed a decrease in fluidity. The re-addition of cardiolipin to the mitochondrial lipids depleted of cardiolipin restored the fluidity to the initial level, thereby confirming the rigidifying effect of cardiolipin in cold-acclimated cells. These results suggest that cardiolipin may be implicated in maintaining consistent fluidity of mitochondrial membranes against change in thermal environment.
在梨形四膜虫进行温度驯化期间，采用硬脂酸探针的自旋标记技术以及薄层色谱法和气液色谱法，研究了来自线粒体、表膜和微粒体这三个膜组分的总脂质的流动性和组成变化。当温度从39℃转变为15℃后，微粒体和表膜脂质中观察到的流动性增加与总不饱和脂肪酸与饱和脂肪酸含量之比的增加相对应。然而，尽管该比例有所增加，但在温度转变后长达10小时内，线粒体脂质的流动性被发现保持恒定。从在39℃生长的四膜虫细胞中分离出的线粒体总脂质的流动性，不会因去除心磷脂而改变，而来自适应15℃环境的细胞的线粒体中的心磷脂耗尽的脂质则显示出流动性降低。将心磷脂重新添加到耗尽心磷脂的线粒体脂质中，可使流动性恢复到初始水平，从而证实了心磷脂在冷驯化细胞中的硬化作用。这些结果表明，心磷脂可能与维持线粒体膜在热环境变化时的一致流动性有关。
