Zwitterionic and acidic glycosphingolipids of the Drosophila melanogaster embryo.
Zwitterionic and acidic glycosphingolipids of the Drosophila melanogaster embryo.
复制标题
DOI：
10.1046/j.1432-1327.2000.01383.x
复制
发表时间：
2000-06
期刊：
影响因子：
--
通讯作者：
A. Seppo;M. Moreland;H. Schweingruber;M. Tiemeyer
中科院分区：
文献类型：
--
作者：
A. Seppo;M. Moreland;H. Schweingruber;M. Tiemeyer
定义鞘糖脂结构的物种服从遗传操作，如果蝇，提供了一个基础，研究机制，调节糖脂的表达。因此，12种主要鞘糖脂中的8种，占果蝇胚胎中脂联碳水化合物的64%，在分离成酸性和两性离子池后被纯化。两性离子脂质具有与一个或多个GlcNAc残基连接的磷酸乙醇胺（PEtn），并且包含系列相关结构的家族。最长的特征性糖脂是一种八糖基神经酰胺，命名为Nz 28，具有以下结构：GalNAc β，4（PEtn-6）GlcNAc β，3Galbeta，3GalNAcalpha，4GalNAc β，4（PEtn-6）GlcNAc β，3 Manbeta，4GlcbetaCer。Nz 28的七糖基（Nz 7）、六糖基（Nz 6）、五糖基（Nz 5）和四糖基（Nz 4）形式从非还原末端依次截短，仅具有一个PEtn部分。主要的酸性脂质，命名为Az 29，具有两个PEtn部分和连接到Gal-延伸的Nz 28的葡萄糖醛酸。另外两种酸性糖脂Az 9和Az 6分别表现出一个PEtn部分和与Az 29和Nz 6相同的己糖和N-乙酰基己糖胺组成。完全扩展的果蝇核心寡糖不同于其他双翅目昆虫的连接在一个单一的糖苷键，一个显着的结构和生物合成的后果的区别。此外，酸性物质占总鞘糖脂的较大比例，并且在果蝇胚胎中，GlcNAc的PEtn取代更完全。分歧的特点可能反映了种间变异或阶段特异性鞘糖脂双翅目的表达。
Defining glycosphingolipid structures in species amenable to genetic manipulation, such as Drosophila melanogaster, provides a foundation for investigating mechanisms that regulate glycolipid expression. Therefore, eight of the 12 major glycosphingolipids, accounting for 64% of lipid-linked carbohydrate in Drosophila embryos, were purified after separation into acidic and zwitterionic pools. The zwitterionic lipids possess phosphoethanolamine (PEtn) linked to one or more GlcNAc residues and comprise a family of serially related structures. The longest characterized glycolipid, an octaosylceramide, designated Nz28, has the structure: GalNAcbeta, 4(PEtn-6)GlcNAcbeta,3Galbeta,3GalNAcalpha,4Ga lNAcbeta, 4(PEtn-6)GlcNAcbeta,3Manbeta,4GlcbetaCer. Heptaosyl (Nz7), hexaosyl (Nz6), pentaosyl (Nz5) and tetraosyl (Nz4) forms of Nz28, sequentially truncated from the nonreducing terminus, possess only one PEtn moiety. The major acidic lipid, designated Az29, possesses two PEtn moieties and a glucuronic acid linked to a Gal-extended Nz28. Two other acidic glycolipids, Az9 and Az6, exhibit one PEtn moiety and the same hexose and N-acetylhexosamine composition as Az29 and Nz6, respectively. The fully extended Drosophila core oligosaccharide differs from that of other dipterans in the linkage at a single glycosidic bond, a distinction with significant structural and biosynthetic consequences. Furthermore, acidic species account for a larger proportion of total glycosphingolipid, and PEtn substitution of GlcNAc is more complete in the Drosophila embryo. Divergent characteristics may reflect interspecies variation or stage-specific glycosphingolipid expression in dipterans.