ARC Centre of Excellence in Synthetic Biology; Centre for Agriculture and the Bioeconomy, Queensland University of Technology; School of Biology and Environmental Science, Queensland University of Technology
Kirill Alexandrov[1] [2] [3], Zhong Guo[1] [2] [3], Oleh Smutok[4] , Gyu Rie Lee [5] [6] [7], Zhenling Cui[1] [2] [3], Haocheng Qianzhu [8], Monika Kish[9], Cagla Ergun Ayva[1] [2] [3], Kejia Wu[5] [6] [7], Roxane Mutschler[1] [2] [3], Colin J. Jackson [1] [8] [10], Maria M Fiorito[1] [2] [3], Andrew Warden[11], Oliver B. Smith[1] [8], Alfredo Quijano-Rubio [12], Thomas Huber[8], Jonathan J. Phillips [9] [13], Gottfried Otting[10], Evgeny Katz[4], David Baker[5] [6] [7]
[1] ARC Centre of Excellence in Synthetic Biology, Australia
[2] Centre for Agriculture and the Bioeconomy, Queensland University of Technology, Brisbane, Australia
[3] School of Biology and Environmental Science, Queensland University of Technology, Brisbane, Australia
[4] Department of Chemistry and Biochemistry, Clarkson University, 8 Clarkson Ave., Potsdam, NY 13699, USA
[5] Department of Biochemistry, University of Washington, Seattle, WA, USA
[6] Institute for Protein Design, University of Washington, Seattle, WA, USA
[7] Howard Hughes Medical Institute, University of Washington, Seattle, WA, USA
[8] Research School of Chemistry, Australian National University, Canberra, ACT, 2601, Australia
[9] Living Systems Institute, University of Exeter, Exeter EX4 4QD, UK
[10] ARC Centre of Excellence for Innovations in Peptide & Protein Science, Australia
[11] Environment Research Unit, Advanced Engineering Biology Future Science Platform, CSIRO Black Mountain Laboratories, Canberra, ACT, 2601, Australia.
[12] Monod Bio, 700 Dexter Ave N, Suite 700, Seattle, WA, 98109, USA
[13] Department of Biosciences, University of Exeter, Exeter, EX4 4QD, UK
Protein allostery enables most biological information processing, yet designing artificial allosteric protein switches remains challenging. We show that machine-learning-designed ligand-binding domains can function as efficient receptors in synthetic allosteric biosensors even without large ligand-induced conformational changes. By combining circularly permuted artificial binders with enzymatic and luminescent reporters, we generated biosensors for steroids, peptides and proteins, including systems with colorimetric, luminescent and electrochemical outputs, as well as intramolecular YES and AND logic gates. Biophysical analyses indicate that ligand binding reduces conformational entropy across the chimera, thereby activating the reporter domain. Importantly, these switches proved functional both in vitro and in vivo. In vitro, they enabled sensitive solution assays and reusable bioelectrodes capable of quantifying steroid hormones with electrochemical readout. In vivo, engineered E. coli expressing steroid-responsive β-lactamase switches displayed ligand-dependent antibiotic resistance and growth. These results establish a versatile platform for programmable biosensing, cellular control and bioelectronics.
Professor Kirill Alexandrov is Professor of Synthetic Biology in the School of Biology and Environmental Science at Queensland University of Technology (QUT). He received his PhD in Cell Biology from the European Molecular Biology Laboratory in Heidelberg and completed postdoctoral training in physical biochemistry at the Max-Planck Institute for Molecular Physiology in Dortmund. Over three decades, his work has integrated protein engineering, structural biology, synthetic biology and high-throughput cell-free screening to build artificial protein switches and biosensors. He pioneered the LEXSY cell-free expression platform and established all-in-vitro pipelines for protein biosensor engineering. His laboratory has developed β-lactamase-based LanM biosensors, AI-designed analyte-binding proteins and programmable allosteric switches for in vitro and in vivo sensing. Professor Alexandrov has authored 168 publications, holds 12 patents, co-founded biotechnology companies in Germany, the United Kingdom and Australia, and has mentored more than 50 graduate students and postdoctoral researchers.
Full name: Professor Kirill Alexandrov
Position/Affiliation: Professor of Synthetic Biology, School of Biology and Environmental Science, Queensland University of Technology (QUT)
Contact number: +61 7 3138 6800
Email: kirill.alexandrov@qut.edu.au
LinkedIn: https://www.linkedin.com/in/kirill-alexandrov-5634718/
ResearchGate: https://www.researchgate.net/scientific-contributions/Kirill-Alexandrov-38693357
Google Scholar: https://scholar.google.com/citations?hl=en&user=F5rZkkUAAAAJ
ORCID: 0000-0002-0957-6511 (https://orcid.org/0000-0002-0957-6511)
Website: https://www.qut.edu.au/about/our-people/academic-profiles/kirill.alexandrov