Künzler K, Eichenberger W, Radunz A
Department of Chemistry and Biochemistry, University of Bern, Switzerland.
Z Naturforsch C J Biosci. 1997 Jul-Aug;52(7-8):487-95.
The cellular localization of the betaine lipids diacylglyceryl-N,N,N-trimethylhomoserine (DGTS) and diacylglycerylhydroxymethyl-N,N,N-trimethyl-beta-alanine (DGTA) was investigated by a) chemical analysis of subcellular fractions and b) immunochemical methods using specific antisera and either fluorescence microscopy or electron microscopy for detection of the label. A homogenate of Lycopodium annotinum (Pteridophyta) was fractionated by differential and density gradient centrifugation. The particulate fractions obtained were analyzed for chlorophyll, cyt c oxidase, NADH-cyt c reductase and DGTS. Non-plastidial fractions were enriched in DGTS and only minor amounts of this lipid could be attributed to chloroplasts. Anti-DGTS and anti-DGTA sera were produced by immunization of rabbits. The monospecificity of the antisera was examined with cells of Chlamydomonas reinhardtii (Chlorophyceae) containing DGTS, Pavlova lutheri (Haptophyceae) containing DGTA and Ochromonas danica (Chrysophyceae) containing both DGTS and DGTA. Euglena gracilis which is free of betaine lipids, was used as a control. For the test, a FITC-coupled goat anti-rabbit antibody was used and detected by fluorescence microscopy. Thin sections of Ochromonas and Pavlova were incubated first with the anti-lipid sera and subsequently with a gold-coupled anti-rabbit serum and then examined in the electron microscope. With Ochromonas, anti-DGTS as well as anti-DGTA sera gave an accumulation of gold label in the cytoplasmic space but not in the chloroplasts. Similar results were obtained with Pavlova using anti-DGTA serum. These results describe for the first time the cytochemical localization of DGTS and DGTA strongly suggesting both these lipids to be associated mainly with non-plastidial structures.
通过以下方法研究了甜菜碱脂二酰甘油 - N，N，N - 三甲基高丝氨酸（DGTS）和二酰甘油羟甲基 - N，N，N - 三甲基 - β - 丙氨酸（DGTA）的细胞定位：a）亚细胞组分的化学分析；b）使用特异性抗血清的免疫化学方法，并通过荧光显微镜或电子显微镜检测标记。对石松（蕨类植物）的匀浆进行差速离心和密度梯度离心分级分离。对获得的颗粒组分进行叶绿素、细胞色素c氧化酶、NADH - 细胞色素c还原酶和DGTS分析。非质体组分中DGTS含量丰富，而叶绿体中仅含有少量这种脂质。通过免疫兔子制备了抗DGTS和抗DGTA血清。用含有DGTS的莱茵衣藻（绿藻纲）细胞、含有DGTA的鲁氏巴夫藻（定鞭藻纲）细胞和同时含有DGTS和DGTA的丹麦赭球藻（金藻纲）细胞检测抗血清的单特异性。不含甜菜碱脂的纤细裸藻用作对照。测试时，使用异硫氰酸荧光素偶联的山羊抗兔抗体，并通过荧光显微镜检测。将丹麦赭球藻和鲁氏巴夫藻的薄片先与抗脂质血清孵育，随后与金偶联的抗兔血清孵育，然后在电子显微镜下检查。对于丹麦赭球藻，抗DGTS血清和抗DGTA血清均使金标记在细胞质空间中积累，而不在叶绿体中积累。使用抗DGTA血清对鲁氏巴夫藻也获得了类似结果。这些结果首次描述了DGTS和DGTA的细胞化学定位，强烈表明这两种脂质主要与非质体结构相关。
