A vesicle capture sensor chip for kinetic analysis of interactions with membrane-bound receptors

A novel sensor chip for use in surface plasmon resonance (SPR) biosensors h as been developed to capture vesicles which may contain membrane-bound rece ptors, Sulforhodamine-containing vesicles were shown by fluorescence micros copy to be immobilized intact on the sensor chip. Binding of cholera toxin to captured vesicles containing ganglioside GM, was demonstrated using SPR, and the derived kinetic and affinity constants were similar to literature values. Biotinylated vesicles captured on the sensor chip were used to bind streptavidin and then biotinylated ss-DNA The hybridization of complementa ry ss-DNA to the immobilized ss-DNA was then analyzed using SPR, The values obtained were similar to those obtained for an identical interaction analy zed using a commercially available streptavidin-containing sensor chip. Bin ding of vancomycin-group antibiotics to captured vesicles containing a bact erial cell wall mucopeptide analogue was demonstrated. No binding of the ba cterial endotoxin Cry1A(c) to captured vesicles containing its cell surface receptor could be demonstrated, (C) 2000 Academic Press.