Interaction between glycophorm and a spin-labeled cholesterol analogue m reconstituted dimynstoylphosphatxdylcholine bilayer vesicles

The interaction between gbcolgnorin and a spin-labeled cholesterol analogue has been tmestigated ~ EPR spee4recopy. In vesicles which were ¢econsti~ted by the freeze and thaw teelmique, ditcher evidenee was obtalned for a reorgamsatlon el the membcane at low protein content {protein/lipid ratio le~ than ! ,300). From the sign exchange interaction we were able to show a ~otem-indneed clustering of the steroid in fluid and tn gel state membranes, Tryptic cleavage of the complete N-termlnus of glycophorin vanishes the effect Whereas the removal el the s, alk aeal residues by nearandnidase digest had no influence on the EPR spectra. The [meraction seems to be eholes~ne spin label specific slnce i t was not ot~.~rv~l with an androstane spin-label