β-Glutamine-mediated self-association of transmembrane β-peptides within lipid bilayers
| Autor: | Claudia Steinem, Ulf Diederichsen, U. Rost |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
Circular dichroism
010405 organic chemistry Chemistry Vesicle General Chemistry 010402 general chemistry 01 natural sciences Transmembrane protein 0104 chemical sciences b-peptides Crystallography Transmembrane domain Förster resonance energy transfer Helix Biophysics Lipid bilayer Protein secondary structure |
| Zdroj: | Chemical Science |
| Popis: | The rational design and synthesis of novel transmembrane β-peptides forming stable secondary structures in a membrane environment are described. Their state of aggregation within the membrane is controlled by hydrogen bonds. Transmembrane β-peptide helices and their association in lipid membranes are still widely unexplored. We designed and synthesized transmembrane β-peptides harboring different numbers of d-β3-glutamine residues (hGln) by solid phase peptide synthesis. By means of circular dichroism spectroscopic measurements, the secondary structure of the β-peptides reconstituted into unilamellar vesicles was determined to be similar to a right-handed 314-helix. Fluorescence spectroscopy using d-β3-tryptophan residues strongly suggested a transmembrane orientation. Two or three hGln served as recognition units between the helices to allow helix–helix assembly driven by hydrogen bond formation. The association state of the transmembrane β-peptides as a function of the number of hGln residues was investigated by fluorescence resonance energy transfer (FRET). Therefore, two fluorescence probes (NBD, TAMRA) were covalently attached to the side chains of the transmembrane β-peptide helices. The results clearly demonstrate that only β-peptides with hGln as recognition units assemble into oligomers, presumably trimers. Temperature dependent FRET experiments further show that the strength of the helix–helix association is a function of the number of hGln residues in the helix. |
| Databáze: | OpenAIRE |
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