Charge Regulation Triggers Condensation of Short Oligopeptides to Polyelectrolytes

Autor(en)

Sebastian P. Pineda, Roman Staňo, Anastasiia Murmiliuk, Pablo M. Blanco, Patricia Montes, Zdeněk Tošner, Ondřej Groborz, Jiří Pánek, Martin Hrubý, Miroslav Štěpánek, Peter Košovan

Abstrakt

Electrostatic interactions between charged macromolecules are ubiquitous in biological systems, and they are important also in materials design. Attraction between oppositely charged molecules is often interpreted as if the molecules had a fixed charge, which is not affected by their interaction. Less commonly, charge regulation is invoked to interpret such interactions, i.e., a change of the charge state in response to a change of the local environment. Although some theoretical and simulation studies suggest that charge regulation plays an important role in intermolecular interactions, experimental evidence supporting such a view is very scarce. In the current study, we used a model system, composed of a long polyanion interacting with cationic oligolysines, containing up to 8 lysine residues. We showed using both simulations and experiments that while these lysines are only weakly charged in the absence of the polyanion, they charge up and condense on the polycations if the pH is close to the pKa of the lysine side chains. We show that the lysines coexist in two distinct populations within the same solution: (1) practically nonionized and free in solution; (2) highly ionized and condensed on the polyanion. Using this model system, we demonstrate under what conditions charge regulation plays a significant role in the interactions of oppositely charged macromolecules and generalize our findings beyond the specific system used here.

Organisation(en)

Computergestützte Physik und Physik der Weichen Materie

Externe Organisation(en)

Charles University Prague, Forschungszentrum Jülich, Universitat de Barcelona, Norwegian University of Science and Technology (NTNU) , Institute of Macromolecular Chemistry AS CR

Journal

JACS Au

Band

4

Seiten

1775–1785

Anzahl der Seiten

11

ISSN

2691-3704

DOI

https://doi.org/10.26434/chemrxiv-2023-8s081-v2

Publikationsdatum

03-2024

Peer-reviewed

Ja

ÖFOS 2012

104017 Physikalische Chemie

Schlagwörter

ASJC Scopus Sachgebiete

Analytical Chemistry, Chemistry (miscellaneous), Physical and Theoretical Chemistry, Organic Chemistry

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/0d79d781-52e6-4352-911e-1f2383e14a0e