GST-CIB1 expressed in Escherichia coli was purified with the use of glutathione-conjugated agarose beads (Sigma). ASK1 variants were translated in vitro in the presence of [35S]methionine with the use of a TNT reticulocyte lysate system (Promega). The 35S-labled proteins were incubated at 4 °C for 4 h in a binding buffer54 (link) with GST-fused proteins immobilized on glutathione-agarose beads. The bound 35S-labeled proteins were eluted from the beads and analyzed by SDS-PAGE and with a Fuji BAS 2500 phosphoimager.
Free full text: Click here