[jeffmoonchop]

Hi all! I know pi stacking can occur between aromatic groups, but is it possible for pi stacking to occur with double bonds? In the lipid MC3, used in the onpattro RNA delivery platform with lipid nanoparticles, the two tails each have two double bonds at similar positions. When these lipids are packed together, is it possible for pi interactions between the unsaturated tails to increase the melting point, or make the structure more stable based on these interactions?

cheers!

[Babcock_Hall]

I do not know the answer to the question of stacking.  However as a general principle, double bonds decrease the melting temperature of fatty acids and increase the fluidity of membranes.  This is usually explained on the basis of poorer packing of the hydrocarbon portions.

[phth]

Yes,

The interaction is much weaker, however.