Catherine Navarre

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Yeast plasma membranes contain a small 55 amino acid hydrophobic polypeptide, Pmp3p, which has high sequence similarity to a novel family of plant polypeptides that are overexpressed under high salt concentration or low temperature treatment. The PMP3 gene is not essential under normal growth conditions. However, its deletion increases the plasma membrane(More)
Rhizosecretion is an attractive technology for the production of recombinant proteins from transgenic plants. However, to date, yields of plant-derived recombinant pharmaceuticals by this method have been too low for commercial viability. Studies conducted focused on three transgenic plant lines grown in hydroponic culture medium, two expressing monoclonal(More)
Peptidases in the extracellular space might affect the integrity of recombinant proteins expressed in, and secreted from, plant cells. To identify extracellular peptidases, we recovered the leaf intercellular fluid from Nicotiana tabacum plants by an infiltration-centrifugation method. The activity of various peptidases was detected by an in vitro assay in(More)
Genes encoding the heavy and light chains of LO-BM2, a therapeutic IgG antibody, were assembled in the tandem or inverted convergent orientation and expressed in Nicotiana tabacum plants and BY-2 suspension cells. The tandem construct allowed higher expression in both expression systems. A similar degradation pattern was observed for the secreted antibody(More)
Thanks to their potential to bind virtually all types of molecules; monoclonal antibodies are in increasing demand as therapeutics and diagnostics. To overcome the overloading of current production facilities, alternative expression systems have been developed, of which plants appear the most promising. In this review, we focus on the expression of(More)
Nicotiana tabacum suspension cells have been widely used to produce monoclonal antibodies, but the yield of secreted antibodies is usually low probably because of proteolytic degradation. Most IgGs that have been expressed in suspension cells have been of the human IgG1 isotype. In this study, we examined whether other isotypes displayed the same(More)
Plant suspension cells are interesting hosts for the heterologous production of pharmacological proteins such as antibodies. They have the advantage to facilitate the containment and the application of good manufacturing practices. Furthermore, antibodies can be secreted to the extracellular medium, which makes the purification steps much simpler. However,(More)
The leaf extracellular space contains several peptidases, most of which are of unknown function. We isolated cDNAs for two extracellular serine carboxypeptidase III genes from tobacco (Nicotiana tabacum), NtSCP1 and NtSCP2, belonging to a phylogenetic clade not yet functionally characterized in plants. NtSCP1 and NtSCP2 are orthologs derived from the two(More)
The purified plasma membrane H(+)-ATPase of Schizosaccharomyces pombe and Saccharomyces cerevisiae display, in addition to the catalytic subunit of 100 kDa, a highly mobile component, soluble in chloroform/methanol. Chloroform/methanol extraction of S. cerevisiae plasma membranes led to isolation of a low molecular weight proteolipid identical to that(More)
Nicotiana tabacum BY-2 suspension cells have several advantages that make them suitable for the production of full-size monoclonal antibodies which can be purified directly from the culture medium. Carbohydrate characterization of an antibody (Lo-BM2) expressed in N. tabacum BY-2 cells showed that the purified Lo-BM2 displays N-glycan homogeneity with a(More)