Study on lysosomes degradation of ricin A chain / 浙江大学学报·医学版

ABSTRACT

<p><b>OBJECTIVE</b>To study lysosomes involvement in the degradation of ricin A chain.</p><p><b>METHODS</b>A lysosome-targeted singal KFERQ was added to the C terminus of rRTA by DNA recombinant technology. A pKK223.3 expression system in E. coli was used to produce recombinant ricine A chain (rRTA) and rRTA-KFERQ. Recombinant proteins were purified by affinity chromatography using Blue-Sepharose 6B. The cytotoxicity of recombinant proteins was measured by the MTT method.</p><p><b>RESULTS</b>Recombinant RTA-KFERQ was 49.87%, 54.18% and 88.68% less cytotoxic than RTA itself on the three cell lines HEPG2, Hela and A549, respectively.</p><p><b>CONCLUSION</b>Lysosomes can degrade, but not completely inactivate RTA in different cells, suggesting cells may have other degradation pathways for RTA.</p>