Electrophoretic analysis of myelin proteolipid protein and its deacylated form.

Myelin proteolipid protein is known to contain covalently bound fatty acid. To determine the contribution of the fatty acid to the multiple bands observed on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the electrophoretic parameters of the proteolipid protein were compared with those of the deacylated form. The relative mobility and proportion of each band, as well as the retardation coefficient and free electrophoretic mobility, were not altered by removal of the fatty acid moiety. Furthermore, the acylated and deacylated forms bound the same amounts of sodium dodecyl sulfate. These data demonstrate that the presence of covalently bound fatty acids does not account for the electrophoretic heterogeneity of the proteolipid.