Bertello L E, Gonçalvez M F, Colli W, de Lederkremer R M
Departamento de Química Orgánica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Argentina.
Biochem J. 1995 Aug 15;310 ( Pt 1)(Pt 1):255-61. doi: 10.1042/bj3100255.
Inositol phospholipids (IPL) from epimastigote forms of Trypanosoma cruzi have been investigated by metabolic labelling with [3H]palmitic acid and by GLC-MS analysis of the lipids obtained from non-labelled parasites. The IPL fraction was separated into phosphatidylinositol (PI) and inositol-phosphoceramide subfractions, the latter accounting for 80-85% of the total IPL. The neutral lipids released from the IPLs by PI-specific phospholipase C (PI-PLC) from Bacillus thuringiensis were analysed by silica-gel and reverse-phase TLC for the radioactive lipids and by GLC-MS for the non-radioactive samples. Ceramides containing dihydrosphingosine and sphingosine with C16:0 and C18:0 fatty acids were identified. The main component in the [3H]palmitic acid-labelled ceramides was palmitoyldihydrospingosine, while in the non-labelled sample the ceramides contained mainly sphingosine. This could reflect partial uptake of phospholipid from the medium. The PI contain both alkylacyl- and diacyl-glycerol lipids, with the ether lipid being more abundant. The latter was identified as 1-O-hexadecylglycerol esterified by C18:2 and C18:1 fatty acids. Interestingly, the same lipid had been identified in the anchor of the 1G7 glycoprotein of T. cruzi metacyclic forms.
已通过用[3H]棕榈酸进行代谢标记以及对从未标记寄生虫中获得的脂质进行气相色谱-质谱（GLC-MS）分析，对克氏锥虫前鞭毛体形式的肌醇磷脂（IPL）展开了研究。IPL组分被分离成磷脂酰肌醇（PI）和肌醇-磷酸神经酰胺亚组分，后者占总IPL的80-85%。通过苏云金芽孢杆菌的PI特异性磷脂酶C（PI-PLC）从IPL中释放出的中性脂质，利用硅胶和反相薄层层析（TLC）分析放射性脂质，并用GLC-MS分析非放射性样品。鉴定出了含有二氢鞘氨醇和鞘氨醇以及C16:0和C18:0脂肪酸的神经酰胺。[3H]棕榈酸标记的神经酰胺中的主要成分是棕榈酰二氢鞘氨醇，而在未标记样品中，神经酰胺主要含有鞘氨醇。这可能反映了从培养基中部分摄取磷脂的情况。PI同时含有烷基酰基甘油和二酰基甘油脂质，其中醚脂质更为丰富。后者被鉴定为被C18:2和C18:1脂肪酸酯化的1-O-十六烷基甘油。有趣的是，在克氏锥虫循环后期形式的1G7糖蛋白的锚定物中也鉴定出了相同的脂质。
