Benning C, Huang Z H, Gage D A
Institut für Genbiologische Forschung Berlin GmbH, Federal Republic of Germany.
Arch Biochem Biophys. 1995 Feb 20;317(1):103-11. doi: 10.1006/abbi.1995.1141.
Cells of the photosynthetic bacterium Rhodobacter sphaeroides grown under phosphate-limiting conditions accumulated nonphosphorous glycolipids and lipids carrying head groups derived from amino acids. Concomitantly, the relative amount of phosphoglycerolipids decreased from 90 to 22 mol% of total polar lipids in the membranes. Two lipids, not detectable in cells grown under standard conditions, were synthesized during phosphate-limited growth. Fast atom bombardment mass spectroscopy, exact mass measurements, 1H NMR spectroscopy, sugar composition analysis, and methylation analysis of the predominant glycolipid led to the identification of the novel compound 1,2-di-O-acyl-3-O-[alpha-D-glucopyranosyl-(1-->4)-O-beta-D-galactopyr anosyl]glycerol. The second lipid was identified as the betaine lipid 1,2-di-O-acyl-[4'-(N,N,N-trimethyl)-homoserine]glycerol by cochromatography employing an authentic standard from Chlamydomonas reinhardtii, fast atom bombardment mass spectroscopy, exact mass measurements, and 1H NMR spectroscopy. Prior to this observation, the occurrence of this lipid was thought to be restricted to lower plants and algae. Apparently, these newly synthesized nonphosphorous lipids, in addition to the sulfo- and the ornithine lipid also found in R. sphaeroides grown under optimal conditions, take over the role of phosphoglycerolipids in phosphate-deprived cells.
在磷酸盐限制条件下生长的球形红细菌光合细胞积累了无磷糖脂和带有源自氨基酸的头部基团的脂质。与此同时，膜中磷酸甘油脂的相对含量从总极性脂质的90 mol%降至22 mol%。在磷酸盐限制生长期间合成了两种在标准条件下生长的细胞中无法检测到的脂质。通过快速原子轰击质谱、精确质量测量、1H NMR光谱、糖组成分析以及对主要糖脂的甲基化分析，鉴定出了新型化合物1,2-二-O-酰基-3-O-[α-D-吡喃葡萄糖基-(1→4)-O-β-D-吡喃半乳糖基]甘油。通过使用莱茵衣藻的真实标准品进行共色谱分析、快速原子轰击质谱、精确质量测量和1H NMR光谱，将第二种脂质鉴定为甜菜碱脂质1,2-二-O-酰基-[4'-(N,N,N-三甲基)-高丝氨酸]甘油。在此观察之前，这种脂质的存在被认为仅限于低等植物和藻类。显然，这些新合成的无磷脂质，除了在最佳条件下生长的球形红细菌中也发现的磺基脂质和鸟氨酸脂质外，在缺磷细胞中取代了磷酸甘油脂的作用。
