(A) Mouse brains were subjected to sequential fractionation as shown, and the fractions were assayed for synapsin and α-synuclein by Western blotting. Note that synapsin is distributed in both the soluble (S100) and pellet (P100) fractions, whereas α-synuclein is primarily found in the soluble fractions; in agreement with previous studies.
(B) Further sucrose-gradient separation of the S100 shows that both proteins are localized within higher density fractions, suggesting organization into higher-order complexes. Densitometry analysis is shown below.