UVliPiD: A UVPD-Based Hierarchical Approach for De Novo Characterization of Lipid A Structures
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- 作者：Lindsay J. Morrison ; W. Ryan Parker ; Dustin D. Holden ; Jeremy C. Henderson ; Joseph M. Boll ; M. Stephen Trent ; Jennifer S. Brodbelt
- 刊名：Analytical Chemistry
- 出版年：2016
- 出版时间：February 2, 2016
- 年：2016
- 卷：88
- 期：3
- 页码：1812-1820
- 全文大小：510K
- ISSN：1520-6882
文摘
The lipid A domain of the endotoxic lipopolysaccharide layer of Gram-negative bacteria is comprised of a diglucosamine backbone to which a variable number of variable length fatty acyl chains are anchored. Traditional characterization of these tails and their linkages by nuclear magnetic resonance (NMR) or mass spectrometry is time-consuming and necessitates databases of pre-existing structures for structural assignment. Here, we introduce an automated de novo approach for characterization of lipid A structures that is completely database-independent. A hierarchical decision-tree MSn method is used in conjunction with a hybrid activation technique, UVPDCID, to acquire characteristic fragmentation patterns of lipid A variants from a number of Gram-negative bacteria. Structural assignments are derived from integration of key features from three to five spectra and automated interpretation is achieved in minutes without the need for pre-existing information or candidate structures. The utility of this strategy is demonstrated for a mixture of lipid A structures from an enzymatically modified E. coli lipid A variant. A total of 27 lipid A structures were discovered, many of which were isomeric, showcasing the need for a rapid de novo approach to lipid A characterization.