BPCPPDYSOE21 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 22: Poster Session III - Charged Soft Matter and Theory and Simulation

CPP 22.3: Poster

Mittwoch, 24. März 2021, 16:30–18:30, CPPp

Quantitative prediction of charge regulation in peptides and model ampholytes — •Peter Košovan, Raju Lunkad, Anastasiia Murmiliuk, Pascal Hebbeker, Zdeněk Tošner, and Miroslav Štěpánek — Department of Physical and Macromolecular Chemistry, Charles University

Weak ampholytes are ubiquitous in nature and commonly found in artificial pH-responsive systems. However, our limited understanding of their charge regulation and the lack of predictive capabilities hinder the bottom-up design of such systems. Here, we used a coarse-grained model of a flexible polymer with weakly ionisable monomer units to quantitatively analyse the ionisation behaviour of two oligopeptidesmodel ampholytes. Our simulations predict differences in the charge states between oligopeptides and monomeric amino acids, showing that not only electrostatic interactions between charged groups but also conformational flexibility plays a key role in the charge regulation. By comparing our simulations with experimental results from potentiometric titration, capillary zone electrophoresis and NMR, we demonstrated that our model reliably predicts the charge state of various peptide sequences. Ultimately, our simulation model is the first step towards understanding the charge regulation in flexible ampholytes, and towards predictive bottom-up design of charge-regulating systems.