The assay development of a molecular marker for transmissible spongiform encephalopathies

The transmissible spongiform encephalopathies are a group of neurodegenerative diseases which include Creutzfeldt-Jakob disease (CJD) in humans, scrapie in sheep, and bovine spongiform encephalopathy (BSE) in cattle. Two-dimensional electrophoresis of proteins was previously used to identify two marker proteins, 130/131, which ate selectively present in the cerebrospinal fluid (CSF) of patients with CJD and not in patients with other dementias. The recent characterization of these proteins 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 isoforms), 14-3-3 gamma, 14-3-3 beta, and 14-3-3 theta are immunoreactive with a 30 kDa marker band from CJD CSF. Silver Staining of two-dimensional electrophoresis separated BSE CSF proteins does not identify a similar marker, However, 14-3-3 immunoreactivity is found in cattle CSF when these proteins are blotted to polyvinylidene difluoride but not when blotted to nitrocellulose.