Ohtsu T, Kimura M T, Katagiri C
Department of Biology, Faculty of Science, Hokkaido University, Sapporo, Japan.
Eur J Biochem. 1998 Mar 15;252(3):608-11. doi: 10.1046/j.1432-1327.1998.2520608.x.
Phospholipids of many cold-tolerant organisms have been reported to contain more unsaturated fatty acids than cold-susceptible organisms, a phenomenon known to maintain membrane fluidity at low temperature. However, we have obtained results to the contrary through a comparison of the membrane phospholipids of six temperate and subtropical species belonging to the Drosophila melanogaster species group. With enhancement of cold tolerance, the percentages of monoenoic acids increased but the percentages of dienoic acids decreased, that is, the number of double bonds in the phospholipid decreased without a marked variation in the percentages of unsaturated fatty acids. Concomitantly, the percentage of fatty acids containing 16 carbon atoms increased, while that of fatty acids with 18 carbon atoms decreased. Since phosphatidylethanolamine is a dominant phospholipid in Drosophila, these changes probably contribute to keeping the homeoviscosity of the cellular membranes in a manner different to that in phosphatidylcholine-rich membranes, thereby increasing cold tolerance.
据报道，许多耐寒生物的磷脂比冷敏感生物含有更多的不饱和脂肪酸，这是一种已知的在低温下维持膜流动性的现象。然而，通过比较黑腹果蝇物种组中的六个温带和亚热带物种的膜磷脂，我们得到了相反的结果。随着耐寒性的增强，单烯酸的百分比增加，但二烯酸的百分比降低，也就是说，磷脂中的双键数量减少，而不饱和脂肪酸的百分比没有明显变化。同时，含16个碳原子的脂肪酸百分比增加，而含18个碳原子的脂肪酸百分比降低。由于磷脂酰乙醇胺是果蝇中的主要磷脂，这些变化可能以不同于富含磷脂酰胆碱的膜的方式有助于保持细胞膜的同质性，从而提高耐寒性。
