Table II.
The major ions observed in MALDI-TOF MS of lipid A isolated from Rhizobium CE3; rgtF complemented CE3, strain ODB32; ΔlpxF mutant (SC506) and rgtF complemented CS506, strain ODB33
| Structure (Figure 4) | Obsa [M−H]− | Calc. [M−H]− | Molecular formula | Proposed composition (penta-acyl lipid A) | Strain |
|---|---|---|---|---|---|
| I-A | 1914.43 | 1914.41 | C106H198N2O26 | GalA-GlcN-GlcNonate, (14:0(3-OH))3,18:0(3-OH), 28:0(27-OH) | CE3 and OBD32 |
| 1886.41 | 1886.39 | C104H194N2O26 | GalA-GlcN-GlcNonate, (14:0(3-OH))3, 16:0(3-OH), 28:0(27-OH) | ||
| 1942.45 | 1942.45 | C108H202N2O26 | GalA-GlcN-GlcNonate, (14:0(3-OH))2,18:0(3-OH), 16:0(3-OH), 28:0(27-OH) | ||
| 1972.44 | 1972.42 | C108H200N2O28 | GalA-GlcN-GlcNonate, (14:0(3-OH))3, 16:0(3-OH), 28:0(27-OH), C4:0(3-OH) | ||
| 2000.47 | 2000.45 | C110H204N2O28 | GalA-GlcN-GlcNonate, (14:0(3-OH))3,18:0(3-OH), 28:0(27-OH), C4:0(3-OH) | ||
| 2028.50 | 2028.45 | C112H208N2O28 | GalA-GlcN-GlcNonate, (14:0(3-OH))2,18:0(3-OH), 16:0(3-OH), 28:0(27-OH), C4:0(3-OH) | ||
| I-B | 1870.39 | 1870.39 | C104H194N2O25 | GalA-GlcN-GlcN, (14:0(3-OH))3, 16:0(3-OH), 28:0(27-OH) | CE3 and OBD32 |
| 1898.42 | 1898.42 | C106H198N2O25 | GalA-GlcN-GlcN, (14:0(3-OH))3,18:0(3-OH), 28:0(27-OH) | ||
| 1926.43 | 1926.45 | C108H202N2O25 | GalA-GlcN-GlcN, (14:0(3-OH))2,18:0(3-OH), 16:0(3-OH), 28:0(27-OH) | ||
| 1942.45 | 1942.41 | C107H198N2O25 | GalA-GlcN-GlcN, (14:0(3-OH))3, 15:0(3-OH), 28:0(27-OH), C4:0(3-OH) | ||
| 1954.42 | 1954.48 | C110H206N2O25 | GalA-GlcN-GlcN, (14:0(3-OH))2, (18:0(3-OH))2, 28:0(27-OH) | ||
| 1956.44 | 1956.43 | C108H200N2O27 | GalA-GlcN-GlcN, (14:0(3-OH))3,16:0(3-OH), 28:0(27-OH), C4:0(3-OH) | ||
| 1970.45 | 1970.44 | C109H202N2O27 | GalA-GlcN-GlcN, (14:0(3-OH))2, 15:0(3-OH), 16:0(3-OH), 28:0(27-OH), C4:0(3-OH) | ||
| 1984.46 | 1984.46 | C110H204N2O27 | GalA-GlcN-GlcN, (14:0(3-OH))3,18:0(3-OH), 28:0(27-OH), C4:0(3-OH) | ||
| 1998.47 | 1998.47 | C111H206N2O27 | GalA-GlcN-GlcN, (14:0(3-OH))2,18:0(3-OH), 15:0(3-OH), 28:0(27-OH), C4:0(3-OH) | ||
| 2012.48 | 2012.49 | C112H208N2O27 | GalA-GlcN-GlcN, (14:0(3-OH))2,18:0(3-OH), 16:0(3-OH), 28:0(27-OH), C4:0(3-OH) | ||
| 2040.48 | 2040.52 | C114H212N2O27 | GalA-GlcN-GlcN, (14:0(3-OH))2, (18:0(3-OH))2, 28:0(27-OH), C4:0(3-OH) | ||
| 2054.46 | 2054.53 | C115H214N2O27 | GalA-GlcN-GlcN, (14:0(3-OH))2, 15:0(3-OH), C18:0(3-OH)2, 28:0(27-OH), C4:0(3-OH) | ||
| II-B | 2074.38 | 2074.45 | C112H206N2O31 | GalA-GlcN-GlcN-GalA, (14:0(3-OH))3,18:0(3-OH), 28:0(27-OH) | OBD32 |
| 2088.39 | 2088.49 | C113H208N2O31 | GalA-GlcN-GlcN-GalA, (14:0(3-OH))2,18:0(3-OH), 15:0(3-OH), 28:0(27-OH) | ||
| 2102.40 | 2102.48 | C114H210N2O31 | GalA-GlcN-GlcN-GalA (14:0(3-OH))2,18:0(3-OH), 16:0(3-OH), 28:0(27-OH) | ||
| 2116.42 | 2116.50 | C115H212N2O31 | GalA-GlcN-GlcN-GalA, (14:0(3-OH)), 15:0(3-OH), 16:0(3-OH),18:0(3-OH), 28:0(27-OH), | ||
| 2132.40 | 2130.46 | C114H208N2O33 | GalA-GlcN-GlcN-GalA, (14:0(3-OH))3, 16:0(3-OH), 28:0(27-OH), C4:0(3-OH) | ||
| 2146.41 | 2146.47 | C115H210N2O33 | GalA-GlcN-GlcN-GalA, (14:0(3-OH))2, 15:0(3-OH), 16:0(3-OH), 28:0(27-OH), C4:0(3-OH) | ||
| 2160.42 | 2160.49 | C116H212N2O33 | GalA-GlcN-GlcN-GalA, (14:0(3-OH))3,18:0(3-OH), 28:0(27-OH), C4:0(3-OH) | ||
| 2174.43 | 2174.51 | C117H214N2O33 | GalA-GlcN-GlcN-GalA, (14:0(3-OH))2,18:0(3-OH), 15:0(3-OH), 28:0(27-OH), C4:0(3-OH) | ||
| 2188.44 | 2188.52 | C118H216N2O33 | GalA-GlcN-GlcN-GalA, (14:0(3-OH))2,18:0(3-OH), 16:0(3-OH), 28:0(27-OH), C4:0(3-OH) | ||
| 2202.44 | 2202.53 | C119H218N2O33 | GalA-GlcN-GlcN-GalA, 14:0(3-OH), 3-OHC15:0, 16:0(3-OH),18:0(3-OH), 28:0(27-OH), C4:0(3-OH) | ||
| 2216.46 | 2216.55 | C120H220N2O33 | GalA-GlcN-GlcN-GalA, (14:0(3-OH))2, (18:0(3-OH))2, 28:0(27-OH), C4:0(3-OH) | ||
| 2230.47 | 2230.57 | C121H222N2O33 | GalA-GlcN-GlcN-GalA, (14:0(3-OH))2, 15:0(3-OH), (18:0(3-OH))2, 28:0(27-OH), C4:0(3-OH) | ||
| III-A | 1790.27 | 1790.32 | C98H187N2O23P | P-GlcN-GlcNonate, (14:0(3-OH))3, 16:0(3-OH), 28:0(27-OH) | CS506 and OBD33 |
| 1804.31 | 1804.33 | C99H189N2O23P | P-GlcN-GlcNonate, (14:0(3-OH))2, 15:0(3-OH), 16:0(3-OH), 28:0(27-OH) | ||
| 1818.32 | 1818.35 | C100H191N2O23P | P-GlcN-GlcNonate, (14:0(3-OH))3,18:0(3-OH), 28:0(27-OH) | ||
| 1832.32 | 1832.37 | C101H193N2O23P | P-GlcN-GlcNonate, (14:0(3-OH))2, 15:0(3-OH),18:0(3-OH), 28:0(27-OH) | ||
| 1846.34 | 1846.38 | C102H195N2O23P | P-GlcN-GlcNonate, (14:0(3-OH))2,18:0(3-OH), 16:0(3-OH), 28:0(27-OH) | ||
| 1876.32 | 1876.36 | C102H193N2O25P | P-GlcN-GlcNonate, (14:0(3-OH))3, 16:0(3-OH), 28:0(27-OH), C4:0(3-OH) | ||
| 1890.35 | 1890.37 | C103H195N2O25P | P-GlcN-GlcNonate, (14:0(3-OH))2, 15:0(3-OH), 16:0(3-OH), 28:0(27-OH), C4:0(3-OH) | ||
| 1904.35 | 1904.39 | C104H197N2O25P | P-GlcN-GlcNonate, (14:0(3-OH))3,18:0(3-OH), 28:0(27-OH), C4:0(3-OH) | ||
| 1918.37 | 1918.40 | C105H199N2O25P | P-GlcN-GlcNonate, (14:0(3-OH))2, 15:0(3-OH),18:0(3-OH), 28:0(27-OH), C4:0(3-OH) | ||
| 1932.38 | 1932.42 | C106H201N2O25P | P-GlcN-GlcNonate, (14:0(3-OH))2,18:0(3-OH),16:0(3-OH), 28:0(27-OH), C4:0(3-OH) | ||
| 1946.38 | 1946.43 | C107H203N2O25P | P-GlcN-GlcNonate, 14:0(3-OH),15:0(3-OH),18:0(3-OH), 16:0(3-OH), 28:0(27-OH), C4:0(3-OH) C4:0(3-OH) |
||
| 1960.38 | 1960.45 | C108H205N2O25P | P-GlcN-GlcNonate, 14:0(3-OH), (16:0(3-OH))2, C18:0(3-OH), C28:0(27-OH), C4:0(3-OH) | ||
| III-B | 1774.29 | 1774.32 | C98H187N2O22P | P-GlcN-GlcN, (14:0(3-OH))3, 16:0(3-OH), 28:0(27-OH) | CS506 and OBD33 |
| 1802.32 | 1802.36 | C100H191N2O22P | P-GlcN-GlcN, (14:0(3-OH))3,18:0(3-OH), 28:0(27-OH) | ||
| 1816.33 | 1816.37 | C101H193N2O22P | P-GlcN-GlcN, (14:0(3-OH))2, 15:0(3-OH),18:0(3-OH), 28:0(27-OH) | ||
| 1830.32 | 1830.39 | C102H195N2O22P | P-GlcN-GlcN, (14:0(3-OH))2,18:0(3-OH), 16:0(3-OH), 28:0(27-OH) | ||
| 1858.30 | 1858.42 | C104H199N2O22P | P-GlcN-GlcN, (14:0(3-OH))2, (18:0(3-OH))2, 28:0(27-OH) | ||
| 1860.32 | 1860.36 | C102H193N2O24P | P-GlcN-GlcN, (14:0(3-OH))3, 16:0(3-OH), C28:0(27-OH), C4:0(3-OH) | ||
| 1874.34 | 1874.38 | C103H193N2O24P | P-GlcN-GlcN, (14:0(3-OH))2, 15:0(3-OH), 16:0(3-OH), 28:0(27-OH), C4:0(3-OH) | ||
| 1888.35 | 1888.39 | C104H197N2O24P | P-GlcN-GlcN, (14:0(3-OH))3,18:0(3-OH), 28:0(27-OH), C4:0(3-OH) | ||
| 1902.36 | 1901.41 | C105H199N2O24P | P-GlcN-GlcN, (14:0(3-OH))2, 15:0(3-OH),18:0(3-OH), 28:0(27-OH), C4:0(3-OH) | ||
| 1916.37 | 1916.42 | C106H201N2O24P | P-GlcN-GlcN, (14:0(3-OH))2,18:0(3-OH), 16:0(3-OH), 28:0(27-OH), C4:0(3-OH) | ||
| 1944.37 | 1944.45 | C108H205N2O24P | P-GlcN-GlcN, (14:0(3-OH))2, (18:0(3-OH))2, 28:0(27-OH), C4:0(3-OH) | ||
| IV-B | 1950.40 | 1950.36 | C104H195N2O28P | P-GlcN-GlcN-GalA, (14:0(3-OH))3, 16:0(3-OH), 28:0(27-OH) | OBD33 |
| 1964.41 | 1964.37 | C105H197N2O28P | P-GlcN-GlcN-GalA, (14:0(3-OH))2, 15:0(3-OH), 16:0(3-OH), 28:0(27-OH) | ||
| 1978.43 | 1978.39 | C106H199N2O28P | P-GlcN-GlcN-GalA, (14:0(3-OH))3,18:0(3-OH), 28:0(27-OH), | ||
| 1992.43 | 1992.40 | C107H201N2O28P | P-GlcN-GlcN-GalA, (14:0(3-OH))2, 15:0(3-OH),18:0(3-OH), 28:0(27-OH) | ||
| 2006.45 | 2006.42 | C108H203N2O28P | P-GlcN-GlcN-GalA, (14:0(3-OH))2,18:0(3-OH), 16:0(3-OH), 28:0(27-OH) | ||
| 2034.47 | 2034.45 | C110H217N2O28P | P-GlcN-GlcN-GalA, (14:0(3-OH))2, (18:0(3-OH))2, 28:0(27-OH) | ||
| 2036.44 | 2036.39 | C108H201N2O30P | P-GlcN-GlcN-GalA, (14:0(3-OH))3, 16:0(3-OH), 28:0(27-OH), C4:0(3-OH) | ||
| 2050.45 | 2050.41 | C109H203N2O30P | P-GlcN-GlcN-GalA, (14:0(3-OH))2, 15:0(3-OH), 16:0(3-OH), 28:0(27-OH), C4:0(3-OH) | ||
| 2064.46 | 2064.42 | C110H205N2O30P | P-GlcN-GlcN-GalA, (14:0(3-OH))3,18:0(3-OH), 28:0(27-OH), C4:0(3-OH) | ||
| 2078.48 | 2078.43 | C111H207N2O30P | P-GlcN-GlcN-GalA, (14:0(3-OH))2, 15:0(3-OH),18:0(3-OH), 28:0(27-OH), C4:0(3-OH) | ||
| 2092.49 | 2092.45 | C112H209N2O30P | P-GlcN-GlcN-GalA, (14:0(3-OH))2,18:0(3-OH), 16:0(3-OH), 28:0(27-OH), C4:0(3-OH) | ||
| 2106.51 | 2106.47 | C113H211N2O30P | P-GlcN-GlcN-GalA, 14:0(3-OH), 15:0(3-OH), 16:0(3-OH),18:0(3-OH), C28:0(27-OH), C4:0(3-OH) | ||
| 2120.52 | 2120.49 | C114H213N2O30P | P-GlcN-GlcN-GalA, (14:0(3-OH))2, (18:0(3-OH))2, 28:0(27-OH), C4:0(3-OH) |
aThe recorded mass-to-charge ratio values represent the monoisotopic [M−H]− ions observed in the negative reflectron mode. The proposed structures for mass-to-charge ratio values highlighted in bold are shown in Figure 2.