Cytoplasmic and cell surface structure of purified liver gap junctions revealed by freeze-drying

After freeze-drying of purified liver gap junction plaques and vesicles the structural features of the inner and outer aspects of purified gap junctions were investigated. No structural details were seen on the cytoplasmic side of the connexions whereas on the cell surface side the connexions were organized in a paracrystalline pattern and exhibited a central depression or pore. We conclude that the central pore through each connexion varies in diameter along its length and that the closing site is located near the cytoplasmic face.