Secretion of a functional single-chain Fv protein in transgenic tobacco plants and cell suspension cultures.
A synthetic gene encoding an anti-phytochrome single-chain Fv (scFv) antibody bearing an N-terminal signal peptide has been used to transform tobacco plants. Immunoblot analysis showed that transformed plants accumulate high levels of scFv protein, accounting for up to 0.5% of the total soluble protein fraction, which could be extracted by simple infiltration and centrifugation of leaf tissue. A substantial proportion of the scFv protein extracted in this way was found to possess antigen-binding activity. Callus cell suspension cultures derived from transformed plants secrete functional scFv protein into the surrounding medium. Compared with the levels of scFv protein observed in plants expressing the native scFv gene, the incorporation of an N-terminal signal peptide, to target the scFv to the apoplast, results in elevated accumulation of the protein.
Firek
S
S
Department of Botany, University of Leicester, UK.
Draper
J
J
Owen
M R
MR
Gandecha
A
A
Cockburn
B
B
Whitelam
G C
GC
D000595:Amino Acid Sequence; D001483:Base Sequence; D001666:Binding Sites, Antibody; D002478:Cells, Cultured; D017931:DNA Primers / Q000737:chemistry; D007128:Immunoglobulin Fragments / Q000235:genetics* / Q000276:immunology; D066298:In Vitro Techniques; D008024:Ligands; D008969:Molecular Sequence Data; D010834:Phytochrome / Q000276:immunology; D010940:Plant Proteins / Q000276:immunology; D030821:Plants, Genetically Modified; D010947:Plants, Toxic; D011993:Recombinant Fusion Proteins / Q000276:immunology / Q000378:metabolism; D014026:Nicotiana
D017931:DNA Primers; D007128:Immunoglobulin Fragments; D008024:Ligands; D010940:Plant Proteins; D011993:Recombinant Fusion Proteins; C055966:immunoglobulin Fv; D010834:Phytochrome