title: Fast plasmid based protein expression analysis in insect cells using an automated SplitGFP screen.
abstract: Recombinant protein expression often presents a bottleneck for the production of proteins for use in many areas of animal-cell biotechnology. Difficult-to-express proteins require the generation of numerous expression constructs, where popular prokaryotic screening systems often fail to identify expression of multi domain or full-length protein constructs. Post-translational modified mammalian proteins require an alternative host system such as insect cells using the Baculovirus Expression Vector System (BEVS). Unfortunately this is time-, labor-, and cost-intensive. It is clearly desirable to find an automated and miniaturized fast multi-sample screening method for protein expression in such systems. With this in mind, in this paper a high-throughput initial expression screening method is described using an automated Microcultivation system in conjunction with fast plasmid based transient transfection in insect cells for the efficient generation of protein constructs. The applicability of the system is demonstrated for the difficult to express Nucleotide-binding Oligomerization Domain-containing protein 2 (NOD2). To enable detection of proper protein expression the rather weak plasmid based expression has been improved by a sensitive inline detection system. Here we present the functionality and application of the sensitive SplitGFP (split green fluorescent protein) detection system in insect cells. The successful expression of constructs is monitored by direct measurement of the fluorescence in the BioLector Microcultivation system. Additionally, we show that the results obtained with our plasmid-based SplitGFP protein expression screen correlate directly to the level of soluble protein produced in BEVS. In conclusion our automated SplitGFP screen outlines a sensitive, fast and reliable method reducing the time and costs required for identifying the optimal expression construct prior to large scale protein production in baculovirus infected insect cells. Biotechnol. Bioeng. 2016;113: 1975-1983. © 2016 The Authors. Biotechnology and Bioengineering Published by Wiley Periodicals, Inc.
authors.affiliation: Recombinant Protein Expression, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124 Braunschweig, Germany.
authors.forename: Maren
authors.initials: M
authors.lastname: Bleckmann
authors.affiliation: Structural Biology of Autophagy, Helmholtz Centre for Infection Research, Braunschweig, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Schmelz
authors.affiliation: Recombinant Protein Expression, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124 Braunschweig, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Schinkowski
authors.affiliation: Structural Biology of Autophagy, Helmholtz Centre for Infection Research, Braunschweig, Germany.
authors.forename: Andrea
authors.initials: A
authors.lastname: Scrima
authors.affiliation: Recombinant Protein Expression, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124 Braunschweig, Germany. joop.vandenheuvel@helmholtz-hzi.de.
authors.forename: Joop
authors.initials: J
authors.lastname: van den Heuvel
mesh_terms: D000818:Animals; D016367:Baculoviridae / Q000235:genetics; D019149:Bioreactors; D003001:Cloning, Molecular / Q000379:methods*; D049452:Green Fluorescent Proteins / Q000235:genetics* / Q000378:metabolism; D010957:Plasmids / Q000235:genetics*; D015202:Protein Engineering; D011993:Recombinant Fusion Proteins / Q000235:genetics* / Q000378:metabolism; D061987:Sf9 Cells
chemical_list: D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins
keywords: Biolector; Hi5 cells; SplitGFP; high throughput screen; insect cells; protein expression screen