Vial H J, Thuet M J, Philippot J R
J Protozool. 1982 May;29(2):258-63. doi: 10.1111/j.1550-7408.1982.tb04023.x.
The metabolism of phospholipids in synchronous Plasmodium falciparum-infected erythrocytes was studied over one cycle of 48 h by the incorporation of labeled palmitate, serine, choline, and myo-inositol into cellular lipids. The rates of incorporation of palmitate and serine into total phospholipids and of choline into phosphatidylcholine (PC) were linear with the maturation of the parasite, increasing by a factor of 2-5.6 according to the precursors. The rate of inositol incorporation into phosphatidylinositol was 9.6 times higher at the schizont stage than at the ring stage, with a marked increase in the second half of the cycle. A significant incorporation of palmitate into triglycerides also occurred during the schizont stage of the parasite. The incorporations of serine and palmitate into phosphatidylethanolamine (PE) and PC showed a net increase at approximately the twentieth hour of the cycle, while the radioactivities recovered in phosphatidylserine (PS) had already reached a maximum by this time. These findings indicate an instantaneous transformation of PS into PE and PC through a decarboxylation of PS into PE, then a methylation of PE into PC during the second half of the cycle. Although PS is a minor component of the Plasmodium parasite, our findings demonstrate the important role of this phospholipid as a precursor of PE and PC, which are major constituents of parasite phospholipids.
通过将标记的棕榈酸、丝氨酸、胆碱和肌醇掺入细胞脂质中，在48小时的一个周期内研究了同步感染恶性疟原虫的红细胞中磷脂的代谢。随着寄生虫的成熟，棕榈酸和丝氨酸掺入总磷脂以及胆碱掺入磷脂酰胆碱（PC）的速率呈线性增加，根据前体不同增加2至5.6倍。在裂殖体阶段，肌醇掺入磷脂酰肌醇的速率比环状体阶段高9.6倍，在周期的后半段有显著增加。在寄生虫的裂殖体阶段，棕榈酸也大量掺入甘油三酯。丝氨酸和棕榈酸掺入磷脂酰乙醇胺（PE）和PC的量在周期大约第20小时出现净增加，而此时磷脂酰丝氨酸（PS）中的放射性已达到最大值。这些发现表明，在周期的后半段，PS通过脱羧转化为PE，然后PE甲基化转化为PC，从而瞬间转化为PE和PC。尽管PS是疟原虫的次要成分，但我们的发现证明了这种磷脂作为PE和PC的前体的重要作用，而PE和PC是寄生虫磷脂的主要成分。
