Ionophoric properties of the proteolipid apoprotein from bovine brain myelin.

Ionophoric properties of the Proteolipid Apoprotein have been assayed. This is a highly purified and delipidated intrinsic myelin membrane protein, isolated from bovine brain white matter. The preparation of myelin membrane vesicles or the incorporation of purified protein into Dimiristoylphosphatidylcholine liposomes have been carried out. According to our results, the myelin Proteolipid protein may act as a Na+ and Rb+ (K+) unidirectional ionophoretic channel, which main physiological role could be related to the maintenance of ionic equilibrium of myelin sheath around the axons.