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.

Evaluation of screening platforms for virus-like particle production with the baculovirus expression vector system in insect cells

“…This led to a saturation of the scattered light signal, even at low cell densities, and consequently false cell count estimates. A previous study demonstrated that the scattered light signal directly correlates with a cell density of up to 3 × 10 6 cells mL −1 using this shaking speed 15 . As the µ-bioreactor was established 16 as a screening tool for bacterial cultivation with cell densities up to 10 g L −1 , cell densities in standard BEVS cultivations should not lead to saturation of the light scattering signal.…”

The Goldilocks Approach: A Review of Employing Design of Experiments in Prokaryotic Recombinant Protein Production

“…With the aid of genetic engineering, a desired gene cloned into a suitable expression vector can be overexpressed as a recombinant protein of interest [34]. Recombinant proteins can be expressed in cell cultures of bacteria [35], yeasts [36], mammalian cells [37,38], plants [39] and insects [40]. However, the prokaryotic systems remains the most attractive hosts due to their low cost, high productivity and rapid production rates [30].…”

Identifying parameters to improve the reproducibility of transient gene expression in High Five cells

“…In order to improve the throughput and sensitivity of detection of successful expression constructs, fast screening strategies using TGE combined with transactivation [29, 30] or the SplitGFP technology [31] have been established. These methods avoid the need to generate high amounts of different recombinant baculoviruses.…”