TABLE 2.

Charged substituents of the classical lipid Aa

SpeciesSubstituent at position 1Substituent at position 4′Formal net chargeb
Escherichia coliPPP−4
Proteus mirabilisPPEtN−1.5
Rhizobium melilotiPP−3
Rhodobacter capsulatusPPEtNPEtN−1
Rhodocyclus gelatinosusPEtNPPEtN−1
Sphaerotilus natansPPPEtN−2.5
Neisseria meningitidisPPEtNPPEtN−2
  • a For references, see reference 735. Abbreviations: PP, pyrophosphate; P, phosphate; PEtN, phosphoethanolamine; PPEtN, pyrophosphoethanolamine.

  • b For simplicity, phosphomonoesters were assumed to have a 1.5 negative charge at neutral pH.