Study Identifies How Bacterial Sphingolipids Increase Membrane Stiffness
Researchers have purified and characterized ceramide phosphoglycerate (CPG), a novel anionic sphingolipid found in bacteria, demonstrating that it increases both membrane stiffness and zeta potential. Many bacterial species are now known to produce sphingolipids, but the biophysical effects of these structurally unique lipids had not previously been measured. Understanding how these lipids alter membrane properties could have broad implications for microbiology and the study of bacterial physiology.
A new study published on bioRxiv reports the purification and biophysical characterization of ceramide phosphoglycerate (CPG), a structurally novel anionic sphingolipid produced by bacteria that has no known eukaryotic counterpart. Using experimental and computational methods, the researchers showed that CPG and its precursor ceramide 1-phosphate (C1P) both increase the magnitude of membrane zeta potential, indicating greater negative surface charge. Critically, both lipids also increase membrane bending stiffness, with CPG producing a greater rigidity effect than either C1P or ceramide alone. These findings address a gap in knowledge that persisted despite recent genetic and lipidomic studies revealing that sphingolipid biosynthesis genes are widespread across bacterial species. The authors suggest that the experimental and computational pipeline developed in this work could be broadly applied to characterize the many other novel bacterial sphingolipids that remain unstudied.
What's missing
As a preprint, this study has not yet undergone peer review, so findings should be treated as preliminary. The study does not specify which bacterial species or ecological contexts CPG is most relevant to, nor does it address potential functional or evolutionary roles of increased membrane stiffness in bacterial survival or pathogenicity. The generalizability of the biophysical findings to intact bacterial cells versus isolated membrane systems is also not fully established.
What different sources said
- bioRxivCenter
Anionic bacterial sphingolipids increase membrane stiffness
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