title: Expression of human butyrylcholinesterase with an engineered glycosylation profile resembling the plasma-derived orthologue.
abstract: Human butyrylcholinesterase (BChE) is considered a candidate bioscavenger of nerve agents for use in pre- and post-exposure treatment. However, the presence and functional necessity of complex N-glycans (i.e. sialylated structures) is a challenging issue in respect to its recombinant expression. Here we transiently co-expressed BChE cDNA in the model plant Nicotiana benthamiana with vectors carrying the genes necessary for in planta protein sialylation. Site-specific sugar profiling of secreted recombinant BChE (rBChE) collected from the intercellular fluid revealed the presence of mono- and di-sialylated N-glycans, which largely resembles to the plasma-derived orthologue. Attempts to increase that sialylation content of rBChE by the over-expression of an additional glycosylation enzyme that generates branched N-glycans (i.e. β1,4-N-acetylglucosaminyl-transferase IV), allowed the production of rBChE decorated with tri-sialylated structures (up to 70%). Sialylated and non-sialylated plant-derived rBChE exhibited functional in vitro activity comparable to that of its commercially available equine-derived counterpart. These results demonstrate the ability of plants to generate valuable proteins with designed sialylated glycosylation profiles optimized for therapeutic efficacy. Moreover, the efficient synthesis of carbohydrates present only in minute amounts on the native protein (tri-sialylated N-glycans) facilitates the generation of a product with superior efficacies and/or new therapeutic functions.
authors.affiliation: Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria.
authors.forename: Jeannine D
authors.initials: JD
authors.lastname: Schneider
authors.forename: Alexandra
authors.initials: A
authors.lastname: Castilho
authors.forename: Laura
authors.initials: L
authors.lastname: Neumann
authors.forename: Friedrich
authors.initials: F
authors.lastname: Altmann
authors.forename: Andreas
authors.initials: A
authors.lastname: Loos
authors.forename: Latha
authors.initials: L
authors.lastname: Kannan
authors.forename: Tsafrir S
authors.initials: TS
authors.lastname: Mor
authors.forename: Herta
authors.initials: H
authors.lastname: Steinkellner
mesh_terms: D002091:Butyrylcholinesterase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D002092:Butyrylthiocholine / Q000032:analysis / Q000378:metabolism; D006031:Glycosylation; D006801:Humans; D019158:N-Acetylneuraminic Acid; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D015202:Protein Engineering; D011994:Recombinant Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism
chemical_list: D011994:Recombinant Proteins; D002092:Butyrylthiocholine; D002091:Butyrylcholinesterase; D019158:N-Acetylneuraminic Acid
keywords: Butyrylcholinesterase; Glycoengineering; Plants; Recombinant biopharmaceuticals; Sialic acid