title: Expression of curcin-transferrin receptor binding peptide fusion protein and its anti-tumor activity.
abstract: Curcin can inhibit the proliferation of tumor cells and promote tumor cell apoptosis, but the cytotoxicity of curcin is not selective for tumors or normal cells. In order to enhance the targeting of the anti-tumor ability of curcin, a transferrin receptor (TfR) binding peptide, TfRBP9, was fused with curcin. The curcin-TfRBP9 gene was cloned into pQE-30 and the recombinant vector pQE-30-curcin-TfRBP9 was established. Then the recombinant vector pQE-30-curcin-TfRBP9 was transferred into Escherichia coli M15. After being induced by 0.5mM IPTG for 6h at 37°C, the expressed quantity of the recombinant protein was about 30% of the total protein. Recombinant curcin-TfRBP9 was expressed in the form of an inclusion body. After dissolution, purification and renaturation, the purity of the recombinant curcin-TfRBP9 reached 95%. Immunofluorescence analysis showed that the TfRBP9 significantly enhanced the ability of the curcin binding to HepG2, and was enriched in the cytoplasm. The curcin-TfRBP9 fusion protein had significant proliferation inhibition effects on the HepG2 cells that over-expressed transferrin receptors, had lower inhibitory effects on the SKBR-3 cells that expressed low transferrin receptors, and had the lowest inhibitory effects on the LO-2 cells that were normal human liver cells. Compared with curcin, the curcin-TfRBP9 induced higher apoptosis rates in the HepG2 cells.
authors.affiliation: College of Pharmacy, Jinan University, Guangzhou 510632, Guangdong, PR China. tzhengq@jnu.edu.cn
authors.forename: Qing
authors.initials: Q
authors.lastname: Zheng
authors.forename: Yao-Ling
authors.initials: YL
authors.lastname: Xiong
authors.forename: Zhi-Jian
authors.initials: ZJ
authors.lastname: Su
authors.forename: Qi-Hao
authors.initials: QH
authors.lastname: Zhang
authors.forename: Xiao-Yong
authors.initials: XY
authors.lastname: Dai
authors.forename: Lin-Yan
authors.initials: LY
authors.lastname: Li
authors.forename: Xue
authors.initials: X
authors.lastname: Xiao
authors.forename: Ya-Dong
authors.initials: YD
authors.lastname: Huang
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry / Q000378:metabolism* / Q000493:pharmacokinetics / Q000494:pharmacology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D005822:Genetic Vectors / Q000235:genetics; D056945:Hep G2 Cells; D006801:Humans; D031286:Jatropha / Q000235:genetics*; D009369:Neoplasms / Q000188:drug therapy / Q000378:metabolism; D010455:Peptides / Q000737:chemistry / Q000235:genetics* / Q000493:pharmacokinetics / Q000494:pharmacology; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000493:pharmacokinetics / Q000494:pharmacology; D010957:Plasmids / Q000235:genetics; D058849:Protein Refolding; D011990:Receptors, Transferrin / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000493:pharmacokinetics / Q000494:pharmacology; D054789:Ribosome Inactivating Proteins, Type 1 / Q000737:chemistry / Q000235:genetics* / Q000493:pharmacokinetics / Q000494:pharmacology
chemical_list: D000970:Antineoplastic Agents; D010455:Peptides; D010940:Plant Proteins; D011990:Receptors, Transferrin; D011993:Recombinant Fusion Proteins; D054789:Ribosome Inactivating Proteins, Type 1; C515388:curcin protein, Jatropha curcas