Conductance properties of artificial lipidic membranes containing a proteolipid from Electrophorus. Response to cholinergic agents.

Previous studies have shown that a special proteolipid extract from the electric organ of Electrophorus showed high affinity binding for acetylcholine and other cholinergic agents. This proteolipid has now been incorporated into ultrathin lipidic membranes, and the membrane resistance was studied. The resistance decreased from 7.

Fine structure of ultrathin artificial membranes : I. Changes by acetylcholine addition in lipid proteolipid membranes.

A special technique for the electron-microscope study of the fine structure of ultrathin artificial membranes is described. Membranes made of total phospholipids of the cerebral cortex and cholesterol showed globular elements of 40 Å embedded in a denser and diffuse matrix. These same elements were also seen organized in a periodic banded pattern.

Conductance changes produced by acetylcholine in lipidic membranes containing a proteolipid from Electrophorus.

Ultrathin lipidic membranes containing one ten-thousandth of a special proteolipid from electric organ of Electrophorus reacted to the addition of acetylcholine by a rapid and transient increase in conductance. Such a change was not induced by choline and is greatly reduced by a previous application of d-tubocurarine. These properties, resembling those from chemically excitable membranes, were not observed with another proteolipid from the same tissue.