title: Synthesis of a ricin toxin B subunit-rotavirus VP7 fusion protein in potato.
abstract: A gene encoding the outer capsid glycoprotein (VP7) of simian rotavirus SA11, was genetically linked to the amino terminus of the ricin toxin B subunit (RTB) isolated from castor-oil plant (Ricinus communis) seeds. To assess fusion protein expression in plant cells, the VP7::RTB fusion gene was transferred into potato (Solanum tuberosum) cells by Agrobacterium tumefaciens-mediated transformation methods and transformed plants regenerated. The fusion gene was detected in transformed potato genomic DNA by polymerase chain reaction DNA amplification methods. Immunoblot analysis with anti-SA11 antiserum as the primary antibody verified the presence of VP7::RTB fusion protein in transformed potato tuber tissues. The plant-synthesized fusion protein bound RTB membrane receptors as measured by asialofetuin-enzyme-linked immunosorbent assay (ELISA). The ELISA results indicated that the VP7::RTB fusion protein was biologically active and made up approx 0.03% of total soluble transformed tuber protein. The biosynthesis of receptor binding VP7::RTB fusion protein in potato tissues demonstrates the feasibility of producing monomeric ricin toxin B subunit adjuvant-virus antigen fusion proteins in crop plants for enhanced immunity.
authors.affiliation: Center for Molecular Biology and Gene Therapy, Department of Biochemistry and Microbiology, School of Medicine, Loma Linda University, Loma Linda, CA 92354, USA.
authors.forename: Nak-Won
authors.initials: NW
authors.lastname: Choi
authors.forename: Mary K
authors.initials: MK
authors.lastname: Estes
authors.forename: William H R
authors.initials: WH
authors.lastname: Langridge
mesh_terms: D016960:Agrobacterium tumefaciens / Q000235:genetics; D000956:Antigens, Viral / Q000096:biosynthesis / Q000235:genetics*; D036022:Capsid Proteins / Q000096:biosynthesis / Q000235:genetics*; D004247:DNA / Q000032:analysis; D018014:Gene Transfer Techniques; D021141:Nucleic Acid Amplification Techniques; D021122:Protein Subunits / Q000737:chemistry; D011993:Recombinant Fusion Proteins / Q000032:analysis / Q000096:biosynthesis; D012276:Ricin / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics* / Q000633:toxicity; D011198:Solanum tuberosum / Q000235:genetics* / Q000378:metabolism* / Q000821:virology; D014118:Toxins, Biological / Q000096:biosynthesis / Q000235:genetics*; D014170:Transformation, Genetic
chemical_list: D000956:Antigens, Viral; D036022:Capsid Proteins; D021122:Protein Subunits; D011993:Recombinant Fusion Proteins; D014118:Toxins, Biological; C050779:VP7 protein, Rotavirus; D004247:DNA; D012276:Ricin