Seid RC, Bone WM, Phillips LR. Identification of ester-linked fatty acids of bacterial endotoxins by negative ion fast atom bombardment mass spectrometry.
Anal Biochem 1986;
155:168-76. [PMID:
3717553 DOI:
10.1016/0003-2697(86)90242-3]
[Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Negative ion fast atom bombardment mass spectrometry (NI-FAB/MS) was employed to characterize the fatty acids esterified to the lipid A backbone of lipopolysaccharides (LPS) of gram-negative bacteria. LPS and their chemically derived lipid A produced readily detectable fragment ions characteristic of fatty acids. The NI-FAB/MS method is specific, yielding ions indicative of ester- but not of amide-bound fatty acids. The mass spectra of Enterobacteriaceae LPS revealed the presence of lauric (m/z 199), myristic (m/z 227), palmitic (m/z 255), and 3-hydroxymyristic (m/z 243) acids. Pseudomonas aeruginosa LPS gave distinctive fragment ions indicative of 3-hydroxydecanoic (m/z 187), lauric, and 2-hydroxylauric (m/z 215) acids. The Neisseria gonorrhoeae LPS could be distinguished from the others due to the presence of ester-linked 3-hydroxylauric acid. All of the LPS gave abundant ions of m/z 177 and 159, which were derived from diphosphoryl substituents. The use of NI-FAB/MS thus allowed rapid identification of lipid A esterified fatty acids without chemical derivatization or gas chromatographic analysis.
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