Studies on the action of myelin basic protein (MBP) in rat brain

The specificity of I125-MBP uptake and subcellular distribution on a discontinuous sucrose density gradient, compared to those of histone H 4 and cytochrome c, showed a high affinity of MBP for mitochondria and heavy synaptosomes, and of histone H 4 for lighter synaptosomes. One heavier synaptosomal subpopulation was almost equally labelled by both proteins. Cytochrome c showed only a low uptake into particular material. Receptor interaction studies of MBP with H3-labelled 5-hydroxytryptamine and naloxone gave negative results.