Logo SFB 746

 

FOR2143


Institute of Physiology
University of Freiburg
Hermann-Herder-Str. 7
79104 Freiburg
Germany
How to find us

Physiology I
N.N.
Kommissarische Leitung:
Prof. Dr. Marlene Bartos

Physiology II
Prof. Dr. Bernd Fakler
Tel. +49 761 203-5176
Fax +49 761 203-5191
[JavaScript Protected Email]

Uni-Logo
You are here: Home News High Temperature Extends the Range of Size Discrimination of Nonionic Polymers by a Biological Nanopore
Document Actions

High Temperature Extends the Range of Size Discrimination of Nonionic Polymers by a Biological Nanopore

Piguet F, Ouldali H, DiscalaF, Breton MF, Behrends JC, Pelta J, Oukhaled A, Nat Sci Reports, http://doi.org/10.1038/srep38675

Dec 08, 2016

We explore the effect of temperature on the interaction of polydisperse mixtures of nonionic poly(ethylene glycol) (PEG) polymers of different average molar masses with the biological nanopore α-hemolysin. In contrast with what has been previously observed with various nanopores and analytes, we find that, for PEGs larger than a threshold molar mass (2000 g/mol, PEG 2000), increasing temperature increases the duration of the PEG/nanopore interaction. In the case of PEG 3400 the duration increases by up to a factor of 100 when the temperature increases from 5 °C to 45 °C. Importantly, we find that increasing temperature extends the polymer size range of application of nanopore-based single-molecule mass spectrometry (Np-SMMS)-type size discrimination. Indeed, in the case of PEG 3400, discrimination of individual molecular species of different monomer number is impossible at room temperature but is achieved when the temperature is raised to 45 °C. We interpret our observations as the consequence of a decrease of PEG solubility and a collapse of PEG molecules with higher temperatures. In addition to expanding the range of application of Np-SMMS to larger nonionic polymers, our findings highlight the crucial role of the polymer solubility for the nanopore detection.

Personal tools