STORAGE OF SAPOSIN-A AND SAPOSIN-D IN INFANTILE NEURONAL CEROID-LIPOFUSCINOSIS

We have isolated storage cytosomes from brain tissue of patients with infantile neuronal ceroid-lipofuscinosis. The purified storage bodies were subjected to compositional analysis which revealed a high content of proteins, accounting for 43% of dry weight. Saposins A and D, also known as sphingolipid activator proteins (SAPs), were shown to consti tute a major portion of the accumulated protein using gel electrophore sis and sequence analysis. This is the first time that saposins have b een found to be stored in any form of neuronal ceroid-lipofuscinosis.