Neuropeptides interact with glycolipid receptors: a surface plasmon resonance study

Using Surface Plasmon Resonance (SPR) we investigated the interaction of seven neuropeptides with different characteristics and beta-amyloid (Abeta42) peptide, with membranes containing gangliosides. A wide range of affinities characterized the bindings (K(D) = 10(-3)- 10(-7) M), following the scheme: for GM1, Abeta42 > DYN > SP = GAL = SOM = BRD > OXY = ENK; for GD1a, Abeta42 = DYN = GAL > SP = SOM = BRD = OXY > ENK and for GT1b, Abeta42 > DYN > SP = GAL > SOM = BRD = OXY > ENK. The ganglioside sugar moiety, specifically the sialic acid, had an important role in the interactions. In general the affinities were higher with polysialo, than with monosialo gangliosides. The sensorgrams describing the interactions of Abeta42 and SP with gangliosides differed from the interactions of the other studied peptides. Ca(2+) promoted changes in peptide-glycolipid interactions.