Figure 6.

Immunoblot analysis of SCD degradation by peripheral, lumenal, and integral membrane protein preparations. Peripheral proteins and lumenal proteins of DSIMs were selectively extracted as described in MATERIALS AND METHODS. The peripheral protein preparation (lanes 1–3) and the lumenal preparation (lanes 4–6) were supplemented with purified SCD where indicated (lanes 2–3 and 5–6). Integral membrane proteins were extracted with 2% DOC/TX100 (lane 7). After incubation, the protein samples were separated by SDS-PAGE, transferred to a nitrocellulose membrane, and probed with rabbit antiserum to a C-terminal peptide of SCD.