Low-SDS Blue native PAGE.

SDS normally is strictly avoided during Blue native (BN) PAGE because it leads to disassembly of protein complexes and unfolding of proteins. Here, we report a modified BN-PAGE procedure, which is based on low-SDS treatment of biological samples prior to native gel electrophoresis. Using mitochondrial OXPHOS complexes from Arabidopsis as a model system, low SDS concentrations are shown to partially dissect protein complexes in a very defined and reproducible way. If combined with 2-D BN/SDS-PAGE, generated subcomplexes and their subunits can be systematically investigated, allowing insights into the internal architecture of protein complexes. Furthermore, a 3-D BN/low-SDS BN/SDS-PAGE system is introduced to facilitate structural analysis of individual protein complexes without their previous purification.