• Bart Van Droogenbroeck
  • Jingyuan Cao
  • Johannes Stadlmann
  • Friedrich Altmann
  • Sarah Colanesi
  • Stefan Hillmer
  • David G Robinson
  • Els Van Lerberge
  • Nancy Terryn
  • Marc Van Montagu
  • Mifang Liang
  • Ann Depicker
  • Geert De Jaeger

View graph of relations

Production of high-value recombinant proteins in transgenic seeds is an attractive and economically feasible alternative to conventional systems based on mammalian cells and bacteria. In contrast to leaves, seeds allow high-level accumulation of recombinant proteins in a relatively small volume and a stable environment. We demonstrate that single-chain variable fragment (scFv)-Fc antibodies, with N-terminal signal sequence and C-terminal KDEL tag, can accumulate to very high levels as bivalent IgG-like antibodies in Arabidopsis thaliana seeds and illustrate that a plant-produced anti-hepatitis A virus scFv-Fc has similar antigen-binding and in vitro neutralizing activities as the corresponding full-length IgG. As expected, most scFv-Fc produced in seeds contained only oligomannose-type N-glycans, but, unexpectedly, 35-40% was never glycosylated. A portion of the scFv-Fc was found in endoplasmic reticulum (ER)-derived compartments delimited by ribosome-associated membranes. Additionally, consistent with the glycosylation data, large amounts of the recombinant protein were deposited in the periplasmic space, implying a direct transport from the ER to the periplasmic space between the plasma membrane and the cell wall. Aberrant localization of the ER chaperones calreticulin and binding protein (BiP) and the endogenous seed storage protein cruciferin in the periplasmic space suggests that overproduction of recombinant scFv-Fc disturbs normal ER retention and protein-sorting mechanisms in the secretory pathway.
Original languageEnglish
JournalProceedings of the National Academy of Sciences of the United States of America
Volume104
Issue number4
Pages (from-to)1430-5
Number of pages6
ISSN0027-8424
DOIs
Publication statusPublished - 2007

    Research areas

  • Arabidopsis, Electrophoresis, Polyacrylamide Gel, Glycosylation, Mass Spectrometry, Microscopy, Electron, Peptide Mapping, Plantibodies, Plants, Genetically Modified, Trypsin

ID: 560578