Osmotic shock stimulates de novo synthesis of two cardiolipins in an extreme halophilic archaeon
Osmotic shock stimulates de novo synthesis of two cardiolipins in an extreme halophilic archaeon
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DOI：
10.1194/jlr.m300329-jlr200
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发表时间：
2004-01-01
影响因子：
6.5
通讯作者：
Corcelli, A
中科院分区：
文献类型：
--
作者：
Lopalco, P;Lobasso, S;Corcelli, A
本报告阐述了极端嗜盐古菌Halorubrum sp.对渗透胁迫的反应，从意大利南部萨沃亚的马尔盖丽塔盐池中分离出来。低渗应力诱导膜脂质组成的相关变化：古菌心磷脂含量显着增加，而磷脂酰甘油（PG）减少。膜分离从这个古菌细胞破坏后，渗透压休克是高度富集古菌心磷脂，并揭示了一种新的磷脂的存在。电喷雾电离质谱和NMR分析显示，这种新型脂质具有磺基-二甘醇-二醚-磷脂酸的结构，即，磷脂二聚体或新的心磷脂类似物。由于NMR分析表明，新的磷脂二聚体中的糖是相同的，并且与作为古细菌膜中主要脂质组分存在的硫酸化二糖基二植烷基甘油二醚（S-DGD-5）的顺序相同，因此将新的磷脂二聚体命名为S-DGD-5-PA。我们的结论是，渗透压休克诱导的两个心磷脂的膜含量的特定增加，并建议PG和S-DGD-5的从头合成的古菌心磷脂和S-DGD-5-PA，分别是中间体。
The present report illustrates the response to osmotic stress of an extreme halophilic archaeon, Halorubrum sp., isolated from the saltern ponds of Margherita di Savoia in southern Italy. The hypotonic stress induces relevant changes in the membrane lipid composition: archaeal cardiolipin content markedly increases, whereas phosphatidylglycerol (PG) decreases. Membranes isolated from this archaeon after cell disruption by osmotic shock are highly enriched in archaeal cardiolipin and reveal the presence of a novel phospholipid. Electrospray ionization mass spectrometry and NMR analyses revealed that this novel lipid has the structure of a sulfo-diglyco-diether-phosphatidic acid, i.e., a phospholipid dimer or a novel cardiolipin analogue. As NMR analyses showed that the sugars in the novel phospholipid dimer are the same and in the same order of a sulfated diglycosyl diphytanylglycerol diether (S-DGD-5) present as a major lipid component in the archaeon membranes, the novel phospholipid dimer was named S-DGD-5-PA. We conclude that osmotic shock induces a specific increase in the membrane content of the two cardiolipins and suggest that PG and S-DGD-5 are intermediates for the de novo synthesis of archaeal cardiolipin and S-DGD-5-PA, respectively.