Regensburg 2025 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
BP: Fachverband Biologische Physik
BP 32: Computational Biophysics II
BP 32.2: Talk
Friday, March 21, 2025, 09:45–10:00, H46
Interactions of Imidazolium with Elastin-Like Polypeptides: A Molecular Dynamics Study — •Julia Keil and Nico F. A. van der Vegt — Technische Universität Darmstadt, Germany
Biological buffers are commonly used to adjust the pH value of protein solutions and are typically assumed not to affect other properties of the system.[1] However, a series of experimental observations suggest buffer-specific effects on protein stability.[2] Despite these findings, studies on these effects remain limited, and the underlying mechanisms are still poorly understood.[2-4]
We performed molecular dynamics simulations at constant pH[4] to investigate the interactions between the buffer imidazolium (IMI) and elastin-like polypeptides (ELPs) that contain chemically different amino acids at their variable positions. Our analyses revealed a local accumulation of imidazole (IMIo) around the ELPs and its hydrogen bonding to the ELP backbone, regardless of the ELP composition. In contrast, interactions with imidazolium (IMI+) were found to depend on the ELP composition. A strong local accumulation of IMI+ was observed around ELPs containing negatively charged groups, accompanied by hydrogen bonding to their side chains. Conversely, local depletion of IMI+ occurred around ELPs with positively charged groups. As a result, the interactions of ELPs with IMI are determined by the specific composition of the ELPs.
[1] Nat. Chem. 2021, 13, 1023-1024 [2] Curr. Opin. Colloid Interface Sci. 2016, 23, 1-9 [3] J. Pharm. Sci. 2017, 106, 3, 713-733 [4] J. Chem. Theory Comput. 2022, 18, 10, 6148-6160
Keywords: protein-buffer interactions; constant pH molecular dynamics; biological buffers; imidazolium; elastin-like polypeptides