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On 9 febbraio 2025 23:24:27 UTC, Gravatar Marco Lamorte:

  • Updated description of resource 2024_Man Nguyen Thi Hong in PREPRINTS WITH DOI from

    **Title:** Molecular Dynamics Simulations Unveil the Aggregation Patterns and Salting Out of Polyarginines at Zwitterionic POPC Bilayers in Solutions of Various Ionic Strengths. **Open access:** Yes **Working group:** WG2 **Resource Type:** DOI provided preprint. **Resource Format:** PDF **Author(s):** Man Nguyen Thi Hong, Mario Vazdar. **Description/Abstract:** This study employs molecular dynamics (MD) simulations to investigate the adsorption and aggregation behavior of simple polyarginine cell-penetrating peptides (CPPs), specifically modeled as R9 peptides, at zwitterionic phosphocholine POPC membranes under varying ionic strengths of two peptide concentrations and two concentrations of NaCl and CaCl2. The results reveal an intriguing phenomenon of R9 aggregation at the membrane, which is dependent on the ionic strength indicating a salting-out effect. As the peptide concentration and ionic strength increase, peptide aggregation also increases, with aggregate lifetimes and sizes showing a corresponding rise, accompanied by the total decrease of adsorbed peptides at the membrane surface. Notably, in high ionic strength environments, large R9 aggregates, such as octamers, are also observed occasionally. The salting-out, typically uncommon for short positively charged peptides, is attributed to the unique properties of arginine amino acid, specifically by its side chain containing amphiphilic guanidinium (Gdm+) ion which makes both intermolecular hydrophobic like-charge Gdm+ – Gdm+ and salt-bridge Gdm+ – C-terminus interactions, where the former are increased with the ionic strength, and the latter decreased due to electrostatic screening. The aggregation behavior of R9 peptides at membranes can also linked to their CPP translocation properties, suggesting that aggregation may aid in translocation across cellular membranes. **Keywords:** **Affiliation(s):** Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague, Czech Republic. Department of Mathematics, Informatics, and Cybernetics, University of Chemistry and Technology, Prague, Czech Republic. **Publication/Creation Date:** April 24, 2024.
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    **Title:** Molecular Dynamics Simulations Unveil the Aggregation Patterns and Salting Out of Polyarginines at Zwitterionic POPC Bilayers in Solutions of Various Ionic Strengths. **Author(s):** Man Nguyen Thi Hong, Mario Vazdar. **DOI:** 10.1101/2024.04.24.590968 **Publication Date:** April 24, 2024. **Resource Type:** Preprint (DOI provided). **Format:** PDF. **Working Group:** WG2. **Affiliation:** Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague, Czech Republic; University of Chemistry and Technology, Prague, Czech Republic. **Open Access:** Yes. **Keywords:** Molecular dynamics, Polyarginines, Cell-penetrating peptides, Salting-out, POPC membranes, Peptide aggregation. **Description:** This preprint investigates the adsorption and aggregation behavior of polyarginine cell-penetrating peptides (CPPs), specifically modeled as R9 peptides, at zwitterionic phosphocholine (POPC) membranes under varying ionic strengths. Using molecular dynamics (MD) simulations, the study reveals an intriguing **salting-out effect**, where peptide aggregation at the membrane increases with peptide concentration and ionic strength. Larger aggregates, such as octamers, are observed in high ionic strength conditions, suggesting a significant impact on CPP translocation across cellular membranes. The results indicate that the unique properties of arginine, particularly its amphiphilic guanidinium (Gdm+) side chain, drive aggregation dynamics through hydrophobic-like Gdm+ – Gdm+ and salt-bridge Gdm+ – C-terminus interactions. This research contributes to the understanding of CPP membrane interactions and their potential role in translocation mechanisms.