Figure 5.

Dissociation kinetics of ¹²⁵I-ChTX. Membranes prepared from COS-1 cells transiently transfected with either α (•) or α+β subunits (⋄) of the maxi-K channel were incubated with ¹²⁵I-ChTX at room temperature in a medium consisting of 10 mM NaCl, 20 mM Tris·HCl (pH 7.4), 0.1% BSA, 0.1% digitonin, and 5 μM paxilline. Dissociation kinetics were initiated by adding 10 nM ChTX and incubating at room temperature for different periods of time. A semilogarithmic transformation of the first-order dissociation rates is shown.