Subcellular fractionation of rapidly transported axonal material in olfactory nerve: evidence for a size- dependent molecule separation during transport.

[(3)H]Leucine applied to the olfactory mucosae of garfish pike results in rapid precursor uptake, incorporation into proteins and export of labeled protein by axoplasmic transport. The resulting characteristic isotope distributions along the nerve have been subjected to subcellular fractionation. More label is found associated with the particulete fraction obtained from the most rapidly moving profile region than from the regions produced by more slowly moving material. The smaller material tends to separate from the larger molecular complexes by trailing behind. The results are discussed in relation to the transport mechanism.