TABLE 2.

Charged substituents of the classical lipid Aa

SpeciesSubstituent at position 1Substituent at position 4′Formal net chargeb
Escherichia coli PPP−4
Proteus mirabilis PPEtN−1.5
Rhizobium meliloti PP−3
Rhodobacter capsulatus PPEtNPEtN−1
Rhodocyclus gelatinosus PEtNPPEtN−1
Sphaerotilus natans PPPEtN−2.5
Neisseria meningitidis PPEtNPPEtN−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.