THE ASSAY DEVELOPMENT OF A MOLECULAR MARKER FOR TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES

The transmissible spongiform encephalopathies are a group of neurodege nerative diseases which include Creutzfeldt-Jakob disease (CJD) in hum ans, scrapie in sheep, and bovine spongiform encephalopathy (BSE) in c attle. Two-dimensional electrophoresis of proteins was previously used to identify two marker proteins, 130/131, which ate selectively prese nt in the cerebrospinal fluid (CSF) of patients with CJD and not in pa tients with other dementias. The recent characterization of these prot eins by amir-io acid sequencing has identified them as members of the 14-3-3 family of proteins. Polyclonal antibodies against 14-3-3 (all i soforms), 14-3-3 gamma, 14-3-3 beta, and 14-3-3 theta are immunoreacti ve with a 30 kDa marker band from CJD CSF. Silver Staining of two-dime nsional electrophoresis separated BSE CSF proteins does not identify a similar marker, However, 14-3-3 immunoreactivity is found in cattle C SF when these proteins are blotted to polyvinylidene difluoride but no t when blotted to nitrocellulose.