Effect of dextran- and poly(ethylene glycol)-bound procion yellow HE-3G on the partition of membranes from calf brain synaptosomes within an aqueous two-phase system

Abstract

Membranes obtained by lysis and Yeda-press treatment of synaptosomes (nerve endings) from calf cortex have been partitioned within the aqueous phases (and the interfaces between them) of a Ficoll—dextran—poly(ethylene glycol)— water two-phase system. By introducing the dye Procion yello HE-3G in the upper phase, bound to poly(ethylene glycol), or in the lower phase, bound to dextran, the partition of the membranes could be strongly affected. The influence on the partition was more pronounced when the dye was bound to dextran. By using a number of two-phase systems in a counter-current distribution process, it was shown that the membrane preparation was inhomogeneous and that the fractions obtained differed in their contents of acethylcholinesterase, succinate dehydrogenase and ATPase. The affinity partitioning effect depended strongly on the concentration of polymer-bound dye. An optimum dye concentration was found when Procion yellow HE-3G was bound to poly(ethylene glycol). When the same dye was bound to dextran, the number of dye molecules per dextran molecule influence the effectiveness of the extraction.