Proteolipid protein and DM-20 are synthesized by Schwann cells, present in myelin membrane, but they are not fatty acylated.

Proteolipid protein (PLP) and DM-20 were intensely labeled after immunoprecipitation of total cellular proteins and myelin proteins labeled with [35S]methionine in nerve slices. These results provided evidence that PLP and DM-20 are incorporated into the myelin membrane following their synthesis in Schwann cells. In contrast, PLP and DM-20 were not fatty acylated after incubation of the nerve slices with [3H]palmitic acid, however, P0 glycoprotein and 24 kDa protein were heavily fatty acylated. The lack of fatty acylation of PLP and DM-20 in the peripheral nervous system suggests that fatty acyltransferase responsible for their acylation is absent or non-functional in the peripheral nervous system.