DETAILED STRUCTURAL CHARACTERIZATION OF LIPID-A - ELECTROSPRAY-IONIZATION COUPLED WITH TANDEM MASS-SPECTROMETRY
DETAILED STRUCTURAL CHARACTERIZATION OF LIPID-A - ELECTROSPRAY-IONIZATION COUPLED WITH TANDEM MASS-SPECTROMETRY
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DOI：
10.1006/abio.1994.1141
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发表时间：
1994-04-01
影响因子：
2.9
通讯作者：
REINHOLD, VN
中科院分区：
文献类型：
--
作者：
CHAN, S;REINHOLD, VN
先前的研究已经确定了单磷脂酰脂质A （MLA）制剂中的特定功能关系。为了将这种理解扩展到所有贡献实体，MLA样品已经使用电喷雾电离，碰撞诱导解离（CID）和串联质谱（MS/MS）进行了结构表征。比较了明尼苏达沙门氏菌Re595与福氏志贺氏菌的样品类型和成分分布。每个样品有超过20个单独的结构，它们在丰度上差别很大，但在组成上差别不大。组分异质性与烷烃链长、“脂质X”型类似物以及核心2-氨基-2-脱氧双糖GlcNH2beta(1-6)GlcNH2的酯化变化直接相关。先前确定的S. minnesota Re595的七烷基结构仅占15%，其中最丰富的物种是六烷基类似物。flexneri MLA的谱图显示不存在任何七酰类似物，五酰成分最丰富。为了确定结构关系，对两个样品中的离子进行了CID碎片化和MS/MS分离。产物离子谱证明是相同的，显示了一系列酰基损失和糖苷裂解片段。由于之前已经确定了S. minnesota Re595 MLA中每个酰基的位置，因此可以对S. flexneri样品的CID光谱中的离子进行结构分配。对这些结构细节的了解、它们的分离和生物学测试可能提供独特的免疫佐剂或阻断选择性有害内毒过程的成分。(C) 1994学术出版社，Inc.
Previous studies have defined specific functional relationships within monophosphoryl lipid A (MLA) preparations. To extend this understanding to all contributing entities, MLA samples have been structurally characterized using electrospray ionization, collision-induced dissociation (CID), and tandem mass spectrometry (MS/MS). MLA profiles of Salmonella minnesota Re595 have been compared with Shigella flexneri for sample type and component distribution. In excess of 20 individual structures compose each sample, which differ considerably in abundance but little in composition. Component heterogeneity can be directly related to alkane chain length, ''lipid X''-type analogs, and variations in esterification to the core 2-amino-2-deoxydisaccharide, GlcNH2beta(1-6)GlcNH2. The previously defined heptaacyl structure in S. minnesota Re595 was identified at only 15% with the most abundant species a hexaacyl analog. Profiles of S. flexneri MLA show an absence of any heptaacyl analog, with the pentaacyl component the most abundant. To confirm structural relationships, ions from both samples were fragmented by CID and separated by MS/MS. Product ion spectra proved to be identical, showing a series of acyl losses and glycosidic cleavage fragments. Since the position of each acyl group has been previously established in S. minnesota Re595 MLA, ions in the CID spectrum of S. flexneri sample could be structurally assigned. Knowledge of these structural details, their isolation, and biological testing may provide components of unique immune adjuvancy or block-selective deleterious endotoxic processes. (C) 1994 Academic Press, Inc.