Our article has been just published on PNAS! In this work we study the effect of specific protein-lipid interactions with a palette of techniques featuring native mass spectrometry, molecular dynamics and channel recording experiments alongside our own structural bioinformatics analysis (on the left in the figure).
We found that within membrane proteins there exists a huge amount of variability on the amount of charged amino acids exposed with lipid heads, and identified proteins that may modulate their function via specific pH-modulated interactions with the neighbouring bilayer. This is exemplified by the protein OmpF, a channel that remained open for longer times in the presence POPG lipids under acidic conditions.
So, what about this “think positive about negative” title? This refers to the observation that probing protein-lipid samples with both positive and negative electrospray ionization (the latter not commonly used in the word of native mass spectrometry) can provide precious insights into specific protein-lipid interactions. This actually, half jokingly, almost became the title of the paper!
Reference (currently in online form): Liko, I., et al., (2018). Lipid binding attenuates channel closure of the outer membrane protein OmpF. PNAS