Use this URL to cite or link to this record in EThOS: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.744290
Title: Rational design of DNA-based lipid membrane pores
Author: Göpfrich, Kerstin
ISNI:       0000 0004 7224 8654
Awarding Body: University of Cambridge
Current Institution: University of Cambridge
Date of Award: 2017
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Abstract:
DNA nanotechnology has revolutionised our capability to shape and control three-dimensional structures at sub-nanometre length scales. In this thesis, we use DNA to build synthetic membrane-inserting channels. Porphyrin and cholesterol tags serve as membrane anchors to facilitate insertion into the lipid membrane. With atomic force microscopy, confocal imaging and ionic current recordings we characterise our DNA nanochannels that mimic their natural protein-based counterparts in form and function. We find that they exhibit voltage-dependent conductance states. Amongst other architectures, we create the largest man-made pore in a lipid membrane to date approaching the electrical diameter of the nuclear pore complex. Pushing the boundaries on the other end of the spectrum, we demonstrate the ultimately smallest DNA membrane pore made from a single membrane-spanning DNA duplex. Thereby, we proof that ion conduction across lipid membranes does not always require a physical channel. With experiments and MD simulations we show that ions flow through a toroidal pore emerging at the DNA-lipid interface around the duplex. Our DNA pores spanning two orders of magnitude in conductance and molecular weight showcase the rational design of synthetic channels inspired by the diversity of nature - from ion channels to porins.
Supervisor: Keyser, Ulrich F. Sponsor: University of Cambridge
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.744290  DOI:
Keywords: DNA nanotechnology ; DNA origami ; ion channel ; nanopore ; biophysics ; ionic current ; electrophysiology ; lipid membrane ; biomimetics ; synthetic membrane pore
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