Setor Litoral, Universidade Federal do Paraná, Matinhos, PR, Brazil.
Int J Biol Macromol. 2012 Nov;51(4):384-91. doi: 10.1016/j.ijbiomac.2012.05.034. Epub 2012 Jun 4.
Lipid-A was isolated by mild acid hydrolysis from lipopolysaccharides extracted from cells of Herbaspirillum seropedicae, strain SMR1, and from two mutants deficient in the biosynthesis of rhamnose (rmlB⁻ and rmlC⁻). Structural analyzes were carried out using MALDI-TOF and derivatization by per-O-trimethylsilylation followed by GC-MS in order to determine monosaccharide and fatty acid composition. De-O-acylation was also performed to determine the presence of N-linked fatty acids. Lipid-A from H. seropedicae SMR1 showed a major structure comprising 2-amino-2-deoxy-glucopyranose-(1→6)-2-amino-2-deoxy-glucopyranose phosphorylated at C4' and C1 positions, each carrying a unit of 4-amino-4-deoxy-arabinose. C2 and C2' positions were substituted by amide-linked 3-hydroxy-dodecanoic acids. Both rhamnose-defective mutants showed similar structure for their lipid-A moieties, except for the lack of 4-amino-4-deoxy-arabinose units attached to phosphoryl groups.
从 Herbaspirillum seropedicae 菌株 SMR1 的脂多糖和两个缺乏鼠李糖生物合成的突变体（rmlB⁻ 和 rmlC⁻）中，通过温和酸水解分离出脂质 A。使用 MALDI-TOF 和通过全三甲基硅化衍生化进行结构分析，然后进行 GC-MS，以确定单糖和脂肪酸组成。还进行了脱酰化以确定是否存在 N-连接脂肪酸。来自 H. seropedicae SMR1 的脂质 A 显示出主要结构，包括 2-氨基-2-去氧-吡喃葡萄糖-(1→6)-2-氨基-2-去氧-吡喃葡萄糖，在 C4' 和 C1 位置磷酸化，每个都携带一个 4-氨基-4-去氧-阿拉伯糖单元。C2 和 C2' 位置被酰胺连接的 3-羟基-十二烷酸取代。两个 rhamnose 缺陷型突变体的脂质 A 部分具有相似的结构，除了缺乏连接到磷酸基团的 4-氨基-4-去氧-阿拉伯糖单元。
