The activity of 2′,3′-cyclic nucleotide 3′-phosphodiesterase in the sciatic nerve of rats was determined during the myelination phase of postnatal development. In contrast to the large increase in activity of this enzyme in myelinating cerebrum and cerebellum, the specific activity of the diesterase in sciatic nerve remains constant. It seems unlikely, therefore, that this diesterase is a component of the myelin sheath in sciatic nerve. Determinations of cyclic nucleotide diesterase activity in demyelinated tissue (plaques) of multiple sclerosis patients showed that the enzyme is nearly completely absent from this tissue. These data confirm and support the view that the diesterase is a component of myelin in the CNS. The diesterase was demonstrated in polyacrylamide gels containing the electrophoretically separated rat CNS myelin proteins by staining for enzymatic activity. The enzyme is tentatively identified as a high molecular weight minor protein component of myelin; it does not correspond in its electrophoretic behavior to either the basic (encephalitogenic) protein or the proteolipid protein of myelin.
All Science Journal Classification (ASJC) codes
- Molecular Biology
- Clinical Neurology
- Developmental Biology