Cholesterol-tagged DNA does not only self-assemble into lipid membranes but also polymersomes – under the right conditions:
R. Luo, K. Göpfrich, I. Platzman & J. P. Spatz. DNA-Based Assembly of Multi-Compartment Polymersome Networks, Advanced Functional Materials, 2003480, 2020. In press.
We interface DNA nanotechnology and actin networks and show that light-triggered contaction breaks the symmetry:
K. Jahnke, M. Weiss, C. Weber, I. Platzman*, K. Göpfrich* & J. P. Spatz*. Engineering Light‐Responsive Contractile Actomyosin Networks with DNA Nanotechnology, Advanced Biosystems 2020. https://doi.org/10.1002/adbi.202000102
We used DNA functionalization and electrocoalescence to filter the content of microfluidic droplets:
C. Frey, K. Göpfrich, S. Pashapour, I. Platzman & J. P. Spatz. Electrocoalescence of Water-in-Oil Droplets with a Continuous Aqueous Phase: Implementation of Controlled Content Release. ACS Omega 2020. https://doi.org/10.1021/acsomega.0c00344
We reconfigure plasmonic DNA origami in microfluidic droplets:
K. Göpfrich*, M. J. Urban, C. Frey, I. Platzman, J. P. Spatz* & N. Liu*. Dynamic Actuation of DNA-Assembled Plasmonic Nanostructures in Microfluidic Cell-Sized Compartments. Nano Letters 20, 1571-1577, 2020. https://doi.org/10.1007/978-981-13-9791-2_11
We contributed a bookchapter on DNA nanopores:
K. Göpfrich & U. F. Keyser. DNA Nanotechnology for Building Sensors, Nanopores and Ion-Channels. In: Biological and Bio-inspired Nanomaterials, 2019. https://doi.org/10.1007/978-981-13-9791-2_11
Our view on synthetic biology published in Heidelberg University’s research magazine Ruperta Carola (mostly in German):
K. Göpfrich, I. Platzman & J. P. Spatz. Aus dem Baukasten der molekularen Ingenieure. Auf dem Weg zur synthetischen Zelle, Ruperto Carola, 106-113 2019. [PDF]
We show that single-stranded DNA overhangs can wrap around a cholesterol-tag and thereby prevent aggregation of cholesterol-modified DNA nanostructures:
A. Ohmann, K. Göpfrich, H. Joshi, R. F. Thompson, D. Sobota, N. A. Ranson, A. Aksimentiev & U. F. Keyser. Controlling aggregation of cholesterol-modified DNA nanostructures. Nucleic Acids Research 47, 11441–11451, 2019. https://doi.org/10.1093/nar/gkz914
We establish a method for the formation of giant unilamellar vesicles for the assembly of synthetic cells, offering straight-forward encapsulation of content:
K. Göpfrich, B. Haller, O. Staufer, Y. Dreher, U. Mersdorf, I. Platzman & J. P. Spatz, One-Pot Assembly of Complex Giant Unilamellar Vesicle-Based Synthetic Cells. ACS Synthetic Biology, 2019. https://doi.org/10.1021/acssynbio.9b00034
Video protocol illustrating the method: https://youtu.be/vOPp97toPAw
We demonstrate a universal strategy for the functionalization of microfluidic droplets by attaching reactive groups and components to cholesterol-tagged DNA handles:
K. Jahnke, M. Weiss, C. Frey, S. Antona, J.-W. Janiesch, I. Platzman, K. Göpfrich* & J. P. Spatz*, Programmable Functionalization of Surfactant-Stabilized Microfluidic Droplets via DNA-Tags. Advanced Functional Materials, 2019. https://doi.org/10.1002/adfm.201808647
By tailoring the charge density at the interface of microfluidic droplets, we control the transition between multicompartment systems and GUVs:
B. Haller, K. Göpfrich, M. Schröter, J.-W. Janiesch, I. Platzman & J. P. Spatz, Charge-controlled microfluidic formation of lipid-based single- and multicompartment systems. Lab on a Chip, 2018. https://doi.org/10.1039/C8LC00582F
In this review, we discuss how microfluidics and DNA nanotechnology can be used as tools to assemble complex synthetic cells.
K. Göpfrich*, I. Platzman* & J. P. Spatz*, Mastering Complexity: Towards Bottom-up Construction of Multifunctional Eukaryotic Synthetic Cells. Trends in Biotechnology, 2018. https://doi.org/10.1016/j.tibtech.2018.03.008
Watch a short video about our review here.
We demonstrate that membrane-spanning DNA nanopores are not just mimics of ion channels: They can also transport flip lipids from one bilayerleaflet to the other, like natural scramblases.
A. Ohmann, C.-Y. Li, C. Maffeo, K. Al Nahas, K. N. Baumann, K. Göpfrich, J. Yoo, U. F. Keyser, A. Aksimentiev, Outperforming nature: synthetic enzyme built from DNA flips lipids of biological membranes at record rates. Nature Communications, 2018. https://doi.org/10.1038/s41467-018-04821-5
In the news in c&en.
Kerstin’s PhD thesis in the group of Prof. Ulrich F. Keyser at the University of Cambridge, on the assembly synthetic membrane pores from DNA.
K. Göpfrich, Rational Design of DNA-Based Lipid Membrane Pores. PhD Thesis, 2017. https://doi.org/10.17863/CAM.15517
Thanks to Gates Cambridge, the Winton Programme for the Physics of Sustainability and the Oppenheimer Trust for their generous support.
We built the largest man-made pore in lipid membranes to date and determine its conductance properties with single-molecule experiments and molecular dynamics simulations:
K. Göpfrich, C.-Y. Li, M. Ricci, S. P. Bhamidimarri, J. Yoo, B. Gyenes, A. Ohmann, M. Winterhalter, A. Aksimentiev & U. F. Keyser, Large-Conductance Transmembrane Porin Made from DNA Origami, ACS Nano, 2016. http://pubs.acs.org/doi/abs/10.1021/acsnano.6b03759
Ion conduction pathways across membranes can be lined by the lipids themselves. We demonstrated the formation of stable DNA-lipid pores induced by a single transmembrane-spanning DNA duplex:
K. Göpfrich, C.-Y. Li, C.-Y., I. Mames, S. P. Bhamidimarri, M. Ricci, J. Yoo, A. Mames, A. Ohmann, M. Winterhalter, E. Stulz, A. Aksimentiev & U. F. Keyser, Ion channels made from a single membrane-spanning DNA duplex. Nano Letters, 2016. http://pubs.acs.org/doi/abs/10.1021/acs.nanolett.6b02039
We study transitions from bound to unbound cluster growth using computational models and DNA-tile self-assembly experiments:
S. Tesoro, K. Göpfrich, T. Kartanas, U. F. Keyser & S. E. Ahnert. Non-deterministic self-assembly with asymmetric interactions can lead to tunable self-limiting cluster growth. Physical Review E, 2016. http://journals.aps.org/pre/abstract/10.1103/PhysRevE.94.022404
We created the smallest membrane-inserting DNA nanostructure to date, approaching the dimensions of natural ion channels:
K. Göpfrich, T. Zettl, A. E. C. Meijering, S. Hernández-Ainsa, S. Kocabey, T. Liedl & U. F. Keyser, DNA-tile structures lead to ionic currents through lipid membranes. Nano Letters, 2015. http://pubs.acs.org/doi/abs/10.1021/acs.nanolett.5b00189
DNA-based membrane pores exhibit voltage-dependent conductance states, reminiscent of gating observed for natural membrane pores:
A. Seifert*, K. Göpfrich*, J. R. Burns, N. Fertig, U. F. Keyser & S. Howorka, Bilayer-spanning DNA nanopores with voltage-switching between open and closed state. ACS Nano, 2014 (*equal contribution). http://pubs.acs.org/doi/abs/10.1021/nn5039433
Two porphyrin-tags anchor a simple DNA nanopore in the lipid membrane and serves as fluorescent dyes at the same time:
J. R. Burns, K. Göpfrich, J. W. Wood, V. V. Thacker, E. Stulz, U. F. Keyser & S. Howorka, Lipid-bilayer-spanning DNA nanopores with a bifunctional porphyrin anchor. Angewandte Chemie International Edition, 2013. http://onlinelibrary.wiley.com/doi/10.1002/anie.201305765/abstract
We modify solid-state nanopores with DNA origami to control their pore size and the positioning of binding sites for specific analytes:
S. Hernández-Ainsa, N. A. W. Bell, V. V. Thacker, K. Göpfrich, K. Misiunas, M. E. Fuentes-Perez, F. Moreno-Herrero & U. F. Keyser, DNA origami nanopores for controlling DNA translocation. ACS Nano, 2013. http://pubs.acs.org/doi/abs/10.1021/nn401759r
The frequency of DNA translocation through the protein nanopore alpha-hemolysin is significantly enhanced at pH 6 compared to pH 8:
K. Göpfrich, C. V. Kulkarni, O. J. Pambos & U. F. Keyser, Lipid nanobilayers to host biological nanopores for DNA translocations. Langmuir, 2013. http://pubs.acs.org/doi/abs/10.1021/la3041506