TABLE 2.

Structural assignments for the major molecular ions from negative-ion MALDI-LIN-TOF mass spectra of de-O-acylated LPS from E. coli F470 and F470(pWQ152)^b

Observed mass (m/z)	Structural assignmenta	Theoretical mass (m/z)	Present in:
			F470	F470 (pWQ152)
3,143.1	(lipidA-Hy37)-Kdo2-Hep3-Hex5-HexN-P-PEtN	3,143.8	+	+
3,062.6	(lipidA-Hy37)-Kdo2-Hep3-Hex5-P2-PEtN	3,062.6	+	+
3,020.3	(lipidA-Hy37)-Kdo2-Hep3-Hex5-P3	3,019.5	+	+
	(lipidA-Hy37)-Kdo2-Hep3-Hex5-HexN-P	3,020.7
2,939.5	(lipidA-Hy37)-Kdo2-Hep3-Hex5-P2	2,939.5	+	+
2,859.6	(lipidA-Hy37)-Kdo2-Hep3-Hex5-P	2,859.6	+	+
2,796.9	(lipidA-Hy37)-Kdo3-Hep3-Hex2-P2-PEtN	2,796.5	−	+
	(lipidA-Hy37)-Kdo3-Hep3-Hex3-PEtN	2,798.7
2,778.0	(lipidA-Hy37)-Kdo2-Hep3-Hex4-P2	2,777.5	−	+
2,754.4	(lipidA-Hy37)-Kdo3-Hep3-Hex2-P3	2,753.4	−	+
	(lipidA-Hy37)-Kdo3-Hep3-Hex3-P1	2,755.6
2,673.6	(lipidA-Hy37)-Kdo3-Hep3-Hex2-P2-PEtN2	2,673.4	−	+
2,655.6	(lipidA-Hy37)-Kdo2-Hep3-Hex2-P3-PEtN	2,656.3	−	+
2,576.0	(lipidA-Hy37)-Kdo2-Hep3-Hex2-P2-PEtN	2,576.3	−	+
2,452.8	(lipidA-Hy37)-Kdo2-Hep3-Hex2-P2	2,453.2	−	+

^alipidA-Hy37 refers to the de-O-acylated lipid A backbone with the structure (GlcN-C14:0-OH)₂.

^bData are shown in Fig. 6.