Molecular dynamics simulation of GM1 gangliosides embedded in a phospholipid membrane

It is found that the GM1 ganglioside molecule, the headgroup of which is bearing a negative charge can form charge pairs with the positively charged choline group of the zwitterionic head of the DOPC molecules. This charge pair can involve either 1 or 2 nearest neighbour DOPC molecules. The observed lifetime of such a charge pair is in the order of a few nanoseconds, whereas the lifetime of a bifurcated charge pairing formed with two DOPC molecules is considerably shorter, being in the order of a few hundred picoseconds. The dipole vector of the polar headgroup of the DOPC molecules charge paired to GM1, represented by the vector pointing from their P to N atom (PN vector) prefers to point straight to the centre of the negative charge located at the C atom of the negatively charged carboxylic (COO−) group of the GM1 molecule.