Figure 1.
Schematic of a connexin hemichannel embedded in a cell membrane with Cys-substituted residues illustrated at three locations, on the extracellular surface, in a crevice facing the extracellular space and in the channel pore. In an open channel, Cys residues on the surface or in crevices are accessible to MTS modification from only one side of the membrane whereas Cys residues in the pore are uniquely accessible from either side.