Table 1

Negative Ion ESI-MS Data and Proposed Compositions for O-deacylated LPS from TEPC-15–nonreactive and –reactive Colonies of Type b H. influenzae (RM 7004)

LPS glycoformObserved [M-3H]3− ions*Molecular massProposed composition
TEPC-15 non-reactiveTEPC-15 reactive
ObservedCalculated‡
Hex3 812.0 812.12439.02439.2Hex3 × Hep3 × Pea1 × KDO1 × P1 × LipidA-OH
 866.72603.12604.3ChoP × Hex3 × Hep3 × PEA1 × KDO1 × P1 ×
 LipidA-OH
Hex4 865.9 865.72601.12601.3Hex3 × Hep3 × Pea1 × KDO1 × P1 × LipidA-OH
 Hex4 × Hep3 × PEA2 ×
 907.02724.02724.5KDO1 × P1 × LipidA-OH
 920.72765.12766.3ChoP × Hex4 × Hep3 × PEA1 × KDO1 × P1 ×
 LipidA-OH
 962.02889.02889.4ChoP × Hex4 × Hep3 × PEA1 × KDO1 × P1 ×
 LipidA-OH
Hex5 919.9 919.82762.42763.5Hex5 × Hep3 × PEA1 × KDO1 × P1 × LipidA-OH
 Hex5 × Hep3 × PEA1 ×
 961.02886.02886.5KDO1 × P1 × LipidA-OH
 975.02928.02928.6ChoP × Hex5 × Hep3 × PEA1 × KDO1 × P1 ×
 LipidA-OH
1016.03051.03051.5ChoP × Hex5 × Hep3 × PEA2 × KDO1 × P1 ×
 LipidA-OH
Hex6 974.1974.02025.02925.6Hex6 × Hep3PEA1 × KDO1 × P1 × LipidA-OH
 Hex6 × Hep3 × PEA2
1015.03048.03048.6KDO1 × P1 × LipidA-OH
1029.03090.03090.7ChoP × Hex6 × Hep3 × PEA1 × KDO1 × P1 × LipidA-OH
Hex71027.83086.43087.8Hex7 × Hep3 × PEA1 KDO1 × P1 × LipidA-OH
Hex81081.63247.83249.9Hex8 × Hep3 × PEA1 × KDO1 × P1 × LipidA-OH
Hex91136.13411.33412.0Hex9 × Hep3 × PEA1 × KDO1 × P1 × LipidA-OH
  • *  The spectra were dominated by molecular peaks corresponding to triply deprotonated ions.  

  •  Average mass units used for calculation of molecular mass values based on proposed compositions as follows: Hex, 162.15; Hep, 192.17; KDO, 220.18; P, 79.98; PEA (phosphoethanolamine), 123.05; ChoP, 165.05.