Expression, purification, characterization, and cytotoxic evaluation of the ML1-STxB fusion protein

Abstract

One of the newest treatment options for cancer is the targeted delivery of the toxin substance to the cancer cells. These toxins should contain different moieties for nding and killing cancer cells. One of these toxins in Mistletoe ML1 protein is an inactive ribosomal protein and can be considered as an anticancer agent. Therefore, it seems that by fusion of ML1 protein with another protein called Shiga toxin B (STxB), which can bind to Gb3 (Globotriosyl Ceramide) receptor that is abundantly expressed on the cancer cells, a recombinant protein with selective permeability may be produced in cancer cells. In the current study, we aimed to produce and purify a fusion protein containing ML1 as a toxic moiety fused to STxB, targeting moiety, and assessing its cytotoxic activities.nanoparticles. Finally, cytotoxic effects of the recombinant proteins were evaluated on the SkBr3 cell line. Analysis of puri ed proteins showed a band of approximately 33 and 41 KDa for rML1-STxB and rML1-STxB nanoparticles, respectively, on SDS-PAGE and western blotting membrane. Finally, statistical analysis showed considerable cytotoxic effects of rML1-STxB on SkBr3 cells at 18.09, 22.52 ng/µL, and higher concentrations. In conclusion, production, puri cation, and encapsulation of rML1-STxB fusion protein with potential speci c toxicity toward cancer cells were successfully achieved. However, further investigation of the cytotoxic effects of this fusion protein on other cancerous cell lines and in vivo cancer models must be applied.