TABLE 1

Glycine lipids in E. coli expressing glsB and glsAc

Predicted size of acyl group (m/z)Mean concn (pmol/109 cells) ± SD
pBAD-choA/glsBpBAD-choBA/glsAB
3-OH-12:035.3 ± 9.0ND
3-OH-14:0 (300.2)b4,070.3 ± 220.9221.3 ± 145.2
3-OH-14:1 (298.2)b118.0 ± 13.3ND
3-OH-15:0 (314.2)b52.4 ± 14.49.2a
3-OH-16:0 (328.2)b3,954.6 ± 215.31,584.9 ± 843.4
3-OH-16:1 (326.2)b6,831.9 ± 264.0382.3 ± 267.1
3-OH-18:0 (356.1)b7.8 ± 1.137.4 ± 33.7
3-OH-18:1 (354.2)b2,539.2 ± 227.51,697.4 ± 994.2
Total monoacylated glycine17,609.5 ± 965.53,923.3 ± 2,283.6
3-OH-14:0 + 12:0 (482.4)bND436.6 ± 228.5
3-OH-16:0 + 12:0/3-OH-14:0 + 14:0 (510.4)bND5,864.1 ± 2,999.9
3-OH-16:1 + 12:0 (508.4)bND652.0 ± 356.9
3-OH-29:0ND240.5 ± 122.1
3-OH-16:0 + 14:0 (538.4)b16.3 ± 5.717,407.0 ± 6,125.0
3-OH-16:1 + 14:0/3-OH-16:0 + 14:1 (536.4)bND5,154.6 ± 2,257.9
3-OH-30:2ND452.0 ± 238.0
3-OH-16:0 + 15:0 (552.4)bND458.8 ± 228.3
3-OH-31:1ND152.3 ± 47.2a
3-OH-16:0 + 16:0 (566.4)b44.5 ± 10.83,901.3 ± 141.9
3-OH-16:0 + 16:1/3-OH-18:1 + 14:0 (564.4)b39.4 ± 14.610,673.8 ± 3,157.3
3-OH-16:1 + 16:1 (562.4)bND1,322.0 ± 429.6
3-OH-33:1ND131.4 ± 74.3
3-OH-16:0 + 18:1/3-OH-18:1 + 16:0 (592.5)b27.7 ± 15.21,540.3 ± 23.7
3-OH-18:1 + 16:1 (590.4)bND1,275.5 ± 218.8
3-OH-36:2ND179.5 ± 43.9
Total diacylated glycine127.9 ± 46.349,841.7 ± 16,693.3
Total acylated pool17,737.453,765.0
  • a Not detected in all biological replicates.

  • b Acylated glycine confirmed by MS/MS fragmentation. The acyl group designation is indicative, based on the predicted number of carbons in the lipid species.

  • c No acylated glycine molecules could be detected in cells carrying the pBAD vector alone. ND, not detected.