Abstract
The expression of high levels of stable and functional proteins remains a bottleneck in many scientific endeavors, including the determination of structures in a high-throughput fashion or the screening for novel active compounds in modern drug discovery. Recently, numerous developments have been made to improve the production of soluble and active proteins in heterologous expression systems. These include modifications to the expression constructs, the introduction of new and/or improved pro- and eukaryotic expression systems, and the development of improved cell-free protein synthesis systems. The introduction of robotics has enabled a massive parallelization of expression experiments, thereby vastly increasing the throughput and, hopefully, the output of such experiments. In addition, the big challenges of recombinant overexpression of membrane and secreted proteins are tackled, and some new methods are reviewed.
Acknowledgements
We are very grateful to our colleagues at Novartis Institute of Biomedical Research (NIBR) Department of Discovery Technologies, who have contributed with ideas and advice to the successful implementation and application of the various technologies for pro- and eukaryotic protein expression; in particular René Amstutz, Jutta Blank, Felix Freuler, Peter Fuerst, Sabine Geisse, Fraser Glickman, Martin Klumpp, Hans Kocher, Christian Ostermeier, Johannes Ottl, Bjoern Philipps, Paul Ramage, Sabine Wellnitz, Hans Widmer and Hartmut Zehender, and we fully appreciate their continuous support, encouragement and enthusiasm for novel technologies in drug discovery.