title: [Study on lysosomes degradation of ricin A chain].
abstract: To study lysosomes involvement in the degradation of ricin A chain.
  
  
  
  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.
  
  
  
  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.
  
  
  
  Lysosomes can degrade, but not completely inactivate RTA in different cells, suggesting cells may have other degradation pathways for RTA.
authors.affiliation: Department of Biochemistry and Molecular Biology, College of Medicine, Zhejiang University, Hangzhou 310006, China.
authors.forename: Chun
authors.initials: C
authors.lastname: Chen
authors.forename: Jin-biao
authors.initials: JB
authors.lastname: Zhan
authors.forename: Fen-ping
authors.initials: FP
authors.lastname: Shen
authors.forename: Jian-gen
authors.initials: JG
authors.lastname: Shen
mesh_terms: D002846:Chromatography, Affinity; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology; D008247:Lysosomes / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D012276:Ricin / Q000235:genetics / Q000378:metabolism*; D014407:Tumor Cells, Cultured
chemical_list: D011994:Recombinant Proteins; D012276:Ricin