Abstract
The configuration of charged polymers is heavily dependent on interactions with surrounding salt ions, typically manifesting as a sensitivity to the bulk ionic strength. Here, we use single-molecule mechanical measurements to show that a charged polysaccharide, hyaluronic acid, shows a surprising regime of insensitivity to ionic strength in the presence of trivalent ions. Using simulations and theory, we propose that this is caused by the formation of a “jacket” of ions, tightly associated with the polymer, whose charge (and thus effect on configuration) is robust against changes in solution composition.
- Received 29 April 2019
- Revised 2 August 2019
DOI:https://doi.org/10.1103/PhysRevLett.123.187801
© 2019 American Physical Society
Physics Subject Headings (PhySH)
Synopsis
Perturbing Polymers with Salty Solutions
Published 29 October 2019
A new model explains the deformation of polymers in an ionic solution in terms of the concentration and distribution of ions.
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