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 (A beta 42) 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, A beta 42 > DYN > SP = GAL. = SOM = BRD > OXY = ENK: for GD1a, A beta 42 = DYN = GAL > SP = SOM = BRD OXY > ENK and for GT1b, A beta 42 > 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 A beta 42 and SP with gangliosides differed from the interactions of the other studied peptides. Ca2+ promoted changes in peptide-glycolipid interactions. (C) 2001 Elsevier Science Inc. All rights reserved.