Redesigning protein function via unnatural amino acids

Redesigning protein function via unnatural amino acids: de novo organelles &
enzyme design
Dr. Stefan M. Schiller,
Bionic Chemistry & synthetic Nanobiotechnology Lab
Albert-Ludwigs-Universität Freiburg,
Zentrum für Biosystemanalyse ZBSA, Habsburger Str. 49, IMTEK Department of
Microsystems Engineering, Georges-Köhler-Allee 103, BIOSS Centre for Biological
Signalling Studies, Schänzlestrasse 18, 79104 Freiburg
The molecular structuring of space can be facilitated by the creation of functional
enclosed space,1 e.g. to confine reactions and to build chemical potentials, and the
formation of structural skeletons presenting molecular functions, both facilitating
interactions, reactions & signaling processes. The combination of the synthetic power of
chemical biology with the rational combination of modular elements within the cell in
synthetic biology allows us to access complex chemical systems in vivo with high
Here we iterate on the use and functionalization of proteins as architectural building
blocks (tectons) to realize a new concept to form de novo organelles and steps towards
their functional programming.2 The latter is currently realized via the genetically
encoded site-specific introduction of bioorthogonal chemical functionalities via
unnatural amino acids. They are introduced by expanding the genetic code via the
redesign of the translational network. First examples for site-specific in vivo
functionalization of such de novo organelles are demonstrated. In order to justify the
complex meaning of the term “organelle” we are currently expanding the functionality of
our de novo organelles via redesigned enzymes. In the frame of the talk a novel strategy
will be presented used to chemically alter enzyme functionalization.3 In this context we
introduce carbohydrate and lipid building blocks allowing to create a modular
combinatorial glycolipid library as tool-box also allowing to use these building blocks to
site-selectively modify proteins.
The combination of our synthetic chemical tool-box of reactions, reagents, methods and
molecules with the design of a protein-based toolbox of biogenic tectons as cellular
building blocks allows to introduce new chemical structures, functions and synthetic
possibilities within the living cell which did not previously exist in nature.4
Schreiber, A., Schiller, S. M “Nanobiotechnology of Protein Compartments: Steps towards
Nanofactories” Bioinspired, Biomimetic and Nanobiomaterials (ICE Virtual Library) 2013,
4, 2, 157-164
Huber, M. C., Schreiber, A., von Olshausen, P., Varga, B. R., Kretz, O., Joch, B., Barnert, S.,
Schubert, R., Eimer, S., Kele, P., Schiller, S. M. “Designer amphiphilic proteins as building blocks
for the intracellular formation of organelle-like compartments” Nature Materials 2014, in
press, DOI: 10.1038/NMAT4118
Yao, C., Schätzle, M., Conradt, D., Lucas, X., Günther, S., Müller, M., Schiller, S. M. “CofactorRedesign in Enzymes: Site-Selective covalent immobilization of Cofactors in Enzymes utilizing
unnatural amino acids” in preparation
Schiller, Stefan M., “Protein Tectons in Synthetic Biology: The expansion of cellular functionality
combining chemical biology of small organic molecules with protein tectons – unnatural amino
acids, protein based biohybrid materials & de novo organelles”, in Synthetic Biology, ed. Giese,
B., von Gleich, A., Pade, C., Wigger, H. (Springer, 2014, ISBN 978-3-319-02782-1