Shimada Haruo, Nemoto Naoki, Shida Yasuo, Oshima Tairo, Yamagishi Akihiko
Department of Molecular Biology, Tokyo University of Pharmacy and Life Science, Hachioji, Tokyo, Japan.
J Bacteriol. 2008 Aug;190(15):5404-11. doi: 10.1128/JB.00415-08. Epub 2008 Jun 6.
Thermoplasma acidophilum HO-62 was grown at different pHs and temperatures, and its polar lipid compositions were determined. Although the number of cyclopentane rings in the caldarchaeol moiety increased when T. acidophilum was cultured at high temperature, the number decreased at low pHs. Glycolipids, phosphoglycolipids, and phospholipids were analyzed by high-performance liquid chromatography with an evaporative light-scattering detector. The amount of caldarchaeol with more than two sugar units on one side increased under low-pH and high-temperature conditions. The amounts of glycolipids increased and those of phosphoglycolipids decreased under these conditions. The proton permeability of the liposomes obtained from the phosphoglycolipids that contained two or more sugar units was lower than that of the liposomes obtained from the phosphoglycolipids that contained one sugar unit. From these results, we propose the hypothesis that T. acidophilum adapts to low pHs and high temperatures by extending sugar chains on their cell surfaces, as well as by varying the number of cyclopentane rings.
嗜酸热原体HO - 62在不同的pH值和温度下培养，并测定其极性脂质组成。尽管当嗜酸热原体在高温下培养时，卡尔德古菌醇部分的环戊烷环数量增加，但在低pH值下数量减少。糖脂、磷酸糖脂和磷脂通过配备蒸发光散射检测器的高效液相色谱进行分析。在低pH值和高温条件下，一侧具有两个以上糖单元的卡尔德古菌醇的量增加。在这些条件下，糖脂的量增加而磷酸糖脂的量减少。从含有两个或更多糖单元的磷酸糖脂获得的脂质体的质子渗透性低于从含有一个糖单元的磷酸糖脂获得的脂质体的质子渗透性。基于这些结果，我们提出一个假设，即嗜酸热原体通过在其细胞表面延长糖链以及改变环戊烷环的数量来适应低pH值和高温。
