Figure 1.

proBDNF is released from cultured cortical neurons. A, Specificity of proBDNF antisera. Media from 293 cells infected with adeno-BDNF were incubated with proBDNF-specific IgY coupled to Sepharose (proBDNF IP) or comparably treated Sepharose in which IgY was not included in the coupling reaction (Control IP). Immunoprecipitated proteins were separated by SDS-PAGE and Western blotted with anti-mature BDNF. B, Conditioned media (40 ml from 1 × 10⁸ cells) and detergent lysates (2 mg; prepared in RIPA buffer) from cultured cortical neurons were immunoprecipitated with anti-proBDNF-coupled Sepharose beads. Immunoprecipitated proteins were separated by SDS-PAGE and Western blotted with anti-mature BDNF antiserum. The positions of proBDNF along with molecular weight markers (numbers in kilodaltons) are indicated. IP, Immunoprecipitation.