Gram-negative bacterial lipid A analysis by negative electrospray ion trap mass spectrometry: Stepwise dissociations of deprotonated species under low energy CID conditions

ABSTRACT We have investigated the lipid A of Francisella tularensis subsp. holarctica strain 1547-57, a type B strain, by using matrix-assisted laser desorption ionization-time-of-flight mass spectrometry, nanoelectrospray quadrupole ion-trap mass spectrometry, and chemical methods. In accordance with the previously published structures of the lipid A from F. tularensis live vaccine strain (LVS) (ATCC 29684) (E. Vinogradov et al., Eur. J. Biochem. 269:6112-6118, 2002), all of the major lipid A forms from strain 1547-57 were tetraacylated. As in the LVS strain, the major fatty acids detected in the F. tularensis 1547-57 lipid A sample included 3-hydroxyoctadecanoic acid, 3-hydroxyhexadecanoic acid, hexadecanoic acid, and tetradecanoic acid. However, several of the lipid A components present in strain 1547-57 were of higher molecular weight than the previously published structures. A major component with an M r of 1,666 was found to contain three C18:0(3-OH) fatty acids, one C16:0 fatty acid, one phosphate group, and one 161-Da moiety. This 161-Da moiety could be removed from the lipid A by treatment with aqueous hydrofluoric acid and was identified as galactosamine following peracetylation and analysis by gas chromatography-mass spectrometry. Detailed investigations of the M r-1,666 species by ion-trap mass spectrometry with multiple stages of fragmentation suggested that the galactosamine-1-phosphate was linked to the reducing terminus of the lipid A. Similar to the modification of lipid A with arabinosamine, lipopolysaccharide species from F. tularensis containing a phosphate-linked galactosamine could potentially influence its intracellular survival by conferring resistance to antimicrobial peptides.

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Characterization of polar lipids of Listeria monocytogenes by HCD and low-energy CAD linear ion-trap mass spectrometry with electrospray ionization

Analytical and Bioanalytical Chemistry ◽

10.1007/s00216-015-8480-1 ◽

2015 ◽

Vol 407 (9) ◽

pp. 2519-2528 ◽

Cited By ~ 17

Author(s):

Raju V. V. Tatituri ◽

Benjamin J. Wolf ◽

Michael B. Brenner ◽

John Turk ◽

Fong-Fu Hsu

Keyword(s):

Mass Spectrometry ◽

Listeria Monocytogenes ◽

Electrospray Ionization ◽

Ion Trap ◽

Low Energy ◽

Polar Lipids ◽

Ion Trap Mass Spectrometry ◽

Linear Ion Trap

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TRIGLYCERIDE COMPOSITION OF SIXTEEN STRAINS OF MARINE DIATOM

Jurnal Ilmu dan Teknologi Kelautan Tropis ◽

10.29244/jitkt.v5i1.7762 ◽

2013 ◽

Vol 5 (1) ◽

Author(s):

Lily M.G. Panggabean ◽

Abdullah Rasyid ◽

Zarrah Duniani ◽

Yana Meliana ◽

Indah Kurniasih

Keyword(s):

Mass Spectrometry ◽

Fatty Acid ◽

Double Bond ◽

Unsaturated Fatty Acid ◽

Ion Trap ◽

Carbon Chain ◽

Highly Unsaturated Fatty Acid ◽

Marine Diatom ◽

Ion Trap Mass Spectrometry ◽

Spectra Analysis

Trigliceride or triacylglicerol (TAG) composition in crude oil of sixteen strain of marine diatom has been detected by spectra analyses on an Electrospray - Ion Trap – Mass Spectrometry (ESI-IT-MS) HCT Bruker-Daltonic GmbH instrument with AgNO3 used as coordination ionization agent. Biomass samples of each microalga strain were taken from early and late stationary cultures in f/2 enriched seawater and algal oils were extracted according to Bligh and Dyer. Results from spectra analysis showed that P-Pt-P (C16:0-C16:1-C16:0) were distinguished in TAG from diatom strains Chaetoceros sp.1, Chaetoceros sp.2, Thalasiossira sp.1, Thalasiossira sp.2, Thalasiossira sp.3, Navicula sp. 1, Navicula sp. 2, Navicula sp. 3, Navicula sp. 4, Nitzschia sp. 2 and Amphora sp. In contrast, TAGs in Melosira sp. included P-P-P (C16:0-C16:0-C16:0) and P-P-O (C16:0-C16:0-C18:1) were identified. TAGs from Chaetoceros sp. were the most varies among samples, i.e. P-Pt-P (C16:0-C16:1-C16:0), A-P-M (C20:4-C16:0-C14:0), P-Pt-Lt (C16:0-C16:1-C18:3), P-Pt-A (C16:0-C16:1-C20:4), D-P-P (C22:6-C16:0-C16:0), A-Ln-P (C20:4-C18:2-C16:0). Various TAGs were also detected in Nitzschia sp.2, i.e. P-Pt-M (C16:0-C16:1-C14:0), P-Pt-P (C16:0-C16:1-C16:0), P-Pt-S (C16:0-C16:1-C18:0), P-Pt-A (C16:0-C16:1-C20:4). TAGs composition in Skeletonema strains that similar to those in Nitzschia sp.1 has longer carbon, i.e. P-P-O (C16:0-C16:0-C18:1), P-O-O (C16:0-C18:1-C18:1) and O-O-O (C18:1-C18:1-C18:1). TAGs with longer carbon chain and more double bond including highly unsaturated fatty acid C20:4 were increased with culture age in diatoms Chaetoceros sp.1, Chaetoceros sp.2, Thalasiossira sp.2, Navicula sp.1 and Nitzschia sp. 2.Keywords: diatom, TAG, ESI-IT-MS, f/2, early and late stationary

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