Engineering of Synthetic Systems

Artificial Protein Scaffolds for Controlled Assembly of Supramolecular Complexes

Artificial protein complexes are of high interest for the build-up of molecular factories because they enable incorporation of multiple enzymatic subunits, and enhanced catalysis of chemical reactions in series. A major limitation, however, remains the preparation of large protein scaffolds onto which catalytic enzymes assemble. Several strategies have been developed for synthesizing scaffolds, for example, using repeated copies of receptor proteins1, or DNA-based scaffolds2. These approaches, however, are limited in terms of scaffold size, specificity and/or stability.

The aim of this project is to synthesize molecular scaffolds using repetitive protein building blocks, and incorporate functional groups for linkage of enzymes. This system design mimics one of the most potent multi-enzyme complexes found in nature that is responsible for cellulose degradation by anaerobic bacteria (i.e., cellulosomes). Using this cellulosomal-mimetic approach, we seek to (1) develop protein scaffolds and enzymes that incorporate complementary functional groups that spontaneously form stable covalent linkages; (2) perform one-pot reactions to self-assemble supramolecular complexes; and (3) characterize and quantitatively validate the system using experiments and modeling. The primary outcome will be scaffold proteins which provide a versatile platform that is generalizable to many different reaction cascades. This work represents a simplified and scalable process to generate supramolecular complexes with novel functionality.

References:
1. García-Alvarez, B. et al. Molecular Architecture and Structural Transitions of a Clostridium thermocellum Mini-Cellulosome. Journal of Molecular Biology 407, 571–580 (2011).
2. Sun, Q., Madan, B., Tsai, S.-L., DeLisa, M. P. & Chen, W. Creation of artificial cellulosomes on DNA scaffolds by zinc finger protein-guided assembly for efficient cellulose hydrolysis. Chemical Communications 50, 1423 (2014).

Articles

D. T. Ta, R. Vanella, M. NashMagnetic separation of elastin-like polypeptide receptors for enrichment of cellular and molecular targets“ Nano Lett. (2017). [Link]

Who works with whom?

Prof. Michael Nash of the University of Basel (Department of Chemistry) leads this project and works with postdoc Ta Duy Tien.

Group

Read more about the Nash Group here.

Collaborations

Michael Nash and his group collaborate with the project led by Konrad Tiefenbacher.