title: Expression of a functional single-chain antibody against GA24/19 in transgenic tobacco.
abstract: An anti-gibberellin A24/19 single-chain Fv gene was constructed from gamma and kappa genes cloned from a hybridoma cell line producing monoclonal antibody against gibberellin A24/19, biosynthetic precursors of gibberellin A4/1 which are biologically active per se. The single-chain Fv gene was introduced into tobacco plants after the binding activity of the single-chain Fv expressed in Escherichia coli was confirmed. When the single-chain Fv expression is targeted to endoplasmic reticulum, the plants could accumulate the single-chain Fv protein with the antigen binding activity up to 3.6% of the total soluble protein. On the other hand, when the expression is targeted to cytosol, accumulation of the single-chain Fv protein was not detected at all. The dwarf phenotype of the transgenic plants expressing the single-chain Fv protein, together with the preliminary analytical data indicating a decreased level of gibberellin A1 in the dwarf transgenics, suggested that the single-chain Fv decreased the concentration of bioactive gibberellins by trapping and inhibiting the metabolism of gibberellin A24 and/or A19 to gibberellin A4 and/or A1.
authors.affiliation: Department of Applied Biological Chemistry, University of Tokyo, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Shimada
authors.forename: Y
authors.initials: Y
authors.lastname: Suzuki
authors.forename: M
authors.initials: M
authors.lastname: Nakajima
authors.forename: U
authors.initials: U
authors.lastname: Conrad
authors.forename: N
authors.initials: N
authors.lastname: Murofushi
authors.forename: I
authors.initials: I
authors.lastname: Yamaguchi
mesh_terms: D000911:Antibodies, Monoclonal / Q000096:biosynthesis* / Q000276:immunology; D000918:Antibody Specificity; D002846:Chromatography, Affinity; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000378:metabolism; D005875:Gibberellins / Q000276:immunology*; D006825:Hybridomas; D030821:Plants, Genetically Modified; D010947:Plants, Toxic; D014026:Nicotiana / Q000235:genetics* / Q000378:metabolism*
chemical_list: D000911:Antibodies, Monoclonal; D005875:Gibberellins; C120176:gibberellin A(24); C120175:gibberellin A(19)