[Fractionation of a sciatic nerve homogenate from normal, trembler and quaking mice on a continuous sucrose gradient].

Two fractions, characterized by biochemical criteria [quantity and density of particulate material, localization of myelin specific protein--Po, P1 and Pr--and of 2',3'-cyclic nucleotide 3'-phosphohydrolase (CNP) and of 5'-nucleotidase], were isolated from sciatic nerve homogenate of normal, Trembler and quaking, young and adult Mice, on a continuous sucrose gradient. The fraction, at 0.58-0.6 M, the richest in membrane particles contains the myelin. The fraction at 0.7-0.75 M should contain the plasma membrane of the Schwann cell which synthesizes myelin.