Tipping the Scale from Disorder to Alpha-helix : Folding of Amphiphilic Peptides in the Presence of Macroscopic and Molecular Interfaces

Dalgicdir, Cahit; Globisch, Christoph; Peter, Christine; Sayar, Mehmet

Tipping the Scale from Disorder to Alpha-helix : Folding of Amphiphilic Peptides in the Presence of Macroscopic and Molecular Interfaces

Dateien

Dalgicdir_0-302884.pdfGröße: 3.95 MBDownloads: 290

Datum

2015

Autor:innen

Dalgicdir, Cahit

Globisch, Christoph

Peter, Christine

Sayar, Mehmet

Open Access-Veröffentlichung

Open Access Gold

Sammlungen

Chemie

Publikationstyp

Zeitschriftenartikel

Publikationsstatus

Published

Erschienen in

PLOS Computational Biology. 2015, 11(8), e1004328. ISSN 1553-734X. eISSN 1553-7358. Available under: doi: 10.1371/journal.pcbi.1004328

Zusammenfassung

Secondary amphiphilicity is inherent to the secondary structural elements of proteins. By forming energetically favorable contacts with each other these amphiphilic building blocks give rise to the formation of a tertiary structure. Small proteins and peptides, on the other hand, are usually too short to form multiple structural elements and cannot stabilize them internally. Therefore, these molecules are often found to be structurally ambiguous up to the point of a large degree of intrinsic disorder in solution. Consequently, their conformational preference is particularly susceptible to environmental conditions such as pH, salts, or presence of interfaces. In this study we use molecular dynamics simulations to analyze the conformational behavior of two synthetic peptides, LKKLLKLLKKLLKL (LK) and EAALAEALAEALAE (EALA), with built-in secondary amphiphilicity upon forming an alpha-helix. We use these model peptides to systematically study their aggregation and the influence of macroscopic and molecular interfaces on their conformational preferences. We show that the peptides are neither random coils in bulk water nor fully formed alpha helices, but adopt multiple conformations and secondary structure elements with short lifetimes. These provide a basis for conformation-selection and population-shift upon environmental changes. Differences in these peptides' response to macroscopic and molecular interfaces (presented by an aggregation partner) can be linked to their inherent alpha-helical tendencies in bulk water. We find that the peptides' aggregation behavior is also strongly affected by presence or absence of an interface, and rather subtly depends on their surface charge and hydrophobicity.

Fachgebiet (DDC)

540 Chemie

Schlagwörter

Hydrogen bonding, Leucine, Lysine, Molecular structure, Alanine, Electrostatics, Peptides, Glutamic acid

Zitieren

ISO 690

DALGICDIR, Cahit, Christoph GLOBISCH, Christine PETER, Mehmet SAYAR, 2015. Tipping the Scale from Disorder to Alpha-helix : Folding of Amphiphilic Peptides in the Presence of Macroscopic and Molecular Interfaces. In: PLOS Computational Biology. 2015, 11(8), e1004328. ISSN 1553-734X. eISSN 1553-7358. Available under: doi: 10.1371/journal.pcbi.1004328

BibTex

@article{Dalgicdir2015Tippi-33233,
  year={2015},
  doi={10.1371/journal.pcbi.1004328},
  title={Tipping the Scale from Disorder to Alpha-helix : Folding of Amphiphilic Peptides in the Presence of Macroscopic and Molecular Interfaces},
  number={8},
  volume={11},
  issn={1553-734X},
  journal={PLOS Computational Biology},
  author={Dalgicdir, Cahit and Globisch, Christoph and Peter, Christine and Sayar, Mehmet},
  note={Article Number: e1004328}
}

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Universitätsbibliographie

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