Functional reconstitution of lens gap junction proteins into proteoliposomes.

Membranes rich in junction complexes were prepared from bovine lens, and the fragments of the membranes were reconstituted into proteoliposomes with a large excess of phosphatidylcholine and dicetylphosphate. The osmotic swelling behavior of these liposomes showed that the lens junction membranes contributed protein components that produced channels with a nominal diameter of 1.4 nm. Most preparations of lens junctions produced rates of osmotic swelling much slower than those found in proteoliposomes containing equivalent amounts of Escherichia coli porin, and we discuss several possible explanations for this observation.