TABLE 3.

MALDI-TOF MS analysis (negative mode) of lipid A fractions of LOSs from N. meningitidis HT1222 and HT1125 and proposed compositions for observed ions^a

Strain	Observed [M − H]− ionb	Proposed composition
HT1222 (ΔlptA::spc)	1794.9	P3GlcN2C12:023OHC14:023OH(C12:0)2
	1714.8	P2GlcN2C12:023OHC14:023OH(C12:0)2
	1634.8	P1GlcN2C12:023OHC14:023OH(C12:0)2
	1532.3	P2GlcN2C12:013OHC14:023OH(C12:0)2
	1452.3	P1GlcN2C12:013OHC14:023OH(C12:0)2
HT1125 (wild type)	1838.1	P2PEAGlcN2C12:023OHC14:023OH(C12:0)2
	1758.0	P1PEAGlcN2C12:023OHC14:023OH(C12:0)2
	1793.3	P3GlcN2C12:023OHC14:023OH(C12:0)2
	1714.9	P2GlcN2C12:023OHC14:023OH(C12:0)2
	1634.8	P1GlcN2C12:023OHC14:023OH(C12:0)2
	1575.5	P1PEAGlcN2C12:013OHC14:023OH(C12:0)2
	1452.3	P1GlcN2C12:013OHC14:023OH(C12:0)2

^aSee also Fig. 5 and 8.

^bThe ions for PEA-containing molecules are shown in bold.