Molecular docking analyses and validation by immunoblotting. (a) Venn diagram depicting a comparison between proteins identified in Jurkat and U937 cell lines. Six proteins including eIF2α, a key regulator in apoptosis signaling pathway, were found to be altered in both cell lines. (b) The potential ligand-binding sites in eIF2α were analyzed and the most probable binding region are labeled with A, B and C. The protein is represented with cartoon model (up). 6S might bind to protein eIF2α at residue Ser51 of the N-terminal domain (down). The protein structure is displayed in ribbon model. (c) Validation of the docking results by three leukemia cell lines Jurkat, U937 and HL-60. Cells treated with or without 6S (15 μM) for 12 h were subjected to western blot analysis using antibodies against eIF2α and p-eIF2α (Ser 51). β-actin was used as reference. Each blot is the representative result of three independent experiments.