The phosphatidylglycerol deficient ΔpgsA mutant of Synechocystis PCC6803 provided a unique experimental system for investigating in vivo retailoring of exogenously added dioleoylphosphatidylglycerol in phosphatidylglycerol-depleted cells. Gas chromatographic analysis of fatty acid composition suggested that diacyl-phosphatidylglycerols were synthesized from the artificial synthetic precursor. The formation of new, retailored lipid species was confirmed by negative-ion electrospray ionization-Fourier-transform ion cyclotron resonance and ion trap tandem mass spectrometry. Various isomeric diacyl-phosphatidylglycerols were identified indicating transesterification of the exogenously added dioleoylphosphatidyl-glycerol at the sn-1 or sn-2 positions. Polyunsaturated fatty acids were incorporated selectively into the sn-1 position. Our experiments with Synechocystis PCC6803/ΔpgsA mutant cells demonstrated lipid remodeling in a prokaryotic photosynthetic bacterium. Our data suggest that the remodeling of diacylphosphatidylglycerol likely involves reactions catalyzed by phospholipase A1 and A2 or acyl-hydrolase, lysophosphatidylglycerol acyltransferase and acyl-lipid desaturases.
|Number of pages||8|
|Journal||Biochimica et Biophysica Acta - Molecular and Cell Biology of Lipids|
|State||Published - 1 Feb 2010|
- Mass spectrometry
- Membrane lipid
- Photosynthetic organism
- Synechocystis PCC6803