Interaction of Self-Assembling β-Sheet Peptides with Phospholipid Monolayers: The Role of Aggregation State, Polarity, Charge and Applied Field

AbstractSelf-assembling peptides are an exemplary class of supramolecular biomaterials of broad biomedical utility. Mechanistic studies on the peptide self-assembly demonstrated the importance of the oligomeric intermediates towards the properties of the supramolecular biomaterials being formed. In this study, we demonstrate how the overall yield of the supramolecular assemblies are moderated through subtle molecular changes in the peptide monomers. This strategy is exemplified with a set of surfactant-like peptides (SLPs) with different β-sheet propensities and charged residues flanking the aggregation domains. By integrating different techniques, we show that these molecular changes can alter both the nucleation propensity of the oligomeric intermediates and the thermodynamic stability of the fibril structures. We demonstrate that the amount of assembled nanofibers are critically defined by the oligomeric nucleation propensities. Our findings offer guidance on designing self-assembling peptides for different biomedical applications, as well as insights into the role of protein gatekeeper sequences in preventing amyloidosis.

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Interaction of self-assembling β-sheet peptides with phospholipid monolayers: The effect of serine, threonine, glutamine and asparagine amino acid side chains

Electrochimica Acta ◽

10.1016/j.electacta.2010.01.023 ◽

2010 ◽

Vol 55 (9) ◽

pp. 3368-3375 ◽

Cited By ~ 13

Author(s):

Elisabeth Protopapa ◽

Lovisa Ringstad ◽

Amalia Aggeli ◽

Andrew Nelson

Keyword(s):

Amino Acid ◽

Side Chains ◽

Self Assembling ◽

Phospholipid Monolayers ◽

Amino Acid Side Chains ◽

Β Sheet

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Role of Sheet-Edge Interactions in β-sheet Self-Assembling Peptide Hydrogels

Biomacromolecules ◽

10.1021/acs.biomac.0c00229 ◽

2020 ◽

Vol 21 (6) ◽

pp. 2285-2297 ◽

Cited By ~ 3

Author(s):

Jacek K. Wychowaniec ◽

Andrew M. Smith ◽

Cosimo Ligorio ◽

Oleksandr O. Mykhaylyk ◽

Aline F. Miller ◽

...

Keyword(s):

Self Assembling ◽

Peptide Hydrogels ◽

Β Sheet

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Electrochemical screening of self-assembling β-sheet peptides using supported phospholipid monolayers

Medical Engineering & Physics ◽

10.1016/j.medengphy.2006.05.002 ◽

2006 ◽

Vol 28 (10) ◽

pp. 944-955 ◽

Cited By ~ 10

Author(s):

E. Protopapa ◽

A. Aggeli ◽

N. Boden ◽

P.F. Knowles ◽

L.C. Salay ◽

...

Keyword(s):

Self Assembling ◽

Phospholipid Monolayers ◽

Β Sheet

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The Role of Hydrophobicity in the Stability and pH-Switchability of (RXDX)4 and Coumarin-RXDX Conjugate β-Sheets

10.26434/chemrxiv.11493060 ◽

2020 ◽

Author(s):

Ryan Weber ◽

Martin McCullagh

Keyword(s):

Biological Imaging ◽

Ph Sensing ◽

Hydrophobic Residue ◽

Ideal Candidate ◽

Self Assembling ◽

Sensing Applications ◽

Β Sheets ◽

The Stability ◽

Dynamics Simulations

pH-switchable, self-assembling materials are of interest in biological imaging and sensing applications. Here we propose that combining the pH-switchability of RXDX (X=Ala, Val, Leu, Ile, Phe) peptides and the optical properties of coumarin creates an ideal candidate for these materials. This suggestion is tested with a thorough set of all-atom molecular dynamics simulations. We first investigate the dependence of pH-switchabiliy on the identity of the hydrophobic residue, X, in the bare (RXDX)4 systems. Increasing the hydrophobicity stabilizes the fiber which, in turn, reduces the pH-switchabilty of the system. This behavior is found to be somewhat transferable to systems in which a single hydrophobic residue is replaced with a coumarin containing amino acid. In this case, conjugates with X=Ala are found to be unstable and both pHs while conjugates with X=Val, Leu, Ile and Phe are found to form stable β-sheets at least at neutral pH. The (RFDF)4-coumarin conjugate is found to have the largest relative entropy value of 0.884 +/- 0.001 between neutral and acidic coumarin ordering distributions. Thus, we posit that coumarin-(RFDF)4 containing peptide sequences are ideal candidates for pH-sensing bioelectronic materials.

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Directive Effect of Chain Length in Modulating Peptide Nano-assemblies

Protein and Peptide Letters ◽

10.2174/0929866527666200224114627 ◽

2020 ◽

Vol 27 (9) ◽

pp. 923-929

Author(s):

Gaurav Pandey ◽

Prem Prakash Das ◽

Vibin Ramakrishnan

Keyword(s):

Electron Microscopy ◽

Amino Acids ◽

Light Scattering ◽

Chain Length ◽

Self Assembly ◽

The Self ◽

Ionic Charge ◽

Self Assembling ◽

Biophysical Techniques

Background: RADA-4 (Ac-RADARADARADARADA-NH2) is the most extensively studied and marketed self-assembling peptide, forming hydrogel, used to create defined threedimensional microenvironments for cell culture applications. Objectives: In this work, we use various biophysical techniques to investigate the length dependency of RADA aggregation and assembly. Methods: We synthesized a series of RADA-N peptides, N ranging from 1 to 4, resulting in four peptides having 4, 8, 12, and 16 amino acids in their sequence. Through a combination of various biophysical methods including thioflavin T fluorescence assay, static right angle light scattering assay, Dynamic Light Scattering (DLS), electron microscopy, CD, and IR spectroscopy, we have examined the role of chain-length on the self-assembly of RADA peptide. Results: Our observations show that the aggregation of ionic, charge-complementary RADA motifcontaining peptides is length-dependent, with N less than 3 are not forming spontaneous selfassemblies. Conclusion: The six biophysical experiments discussed in this paper validate the significance of chain-length on the epitaxial growth of RADA peptide self-assembly.

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Sticky ends in a self-assembling ABA triblock copolymer: the role of ureas in stimuli-responsive hydrogels

Molecular Systems Design & Engineering ◽

10.1039/c8me00063h ◽

2019 ◽

Vol 4 (1) ◽

pp. 91-102 ◽

Cited By ~ 5

Author(s):

Ryan T. Shafranek ◽

Joel D. Leger ◽

Song Zhang ◽

Munira Khalil ◽

Xiaodan Gu ◽

...

Keyword(s):

Self Assembly ◽

Viscoelastic Properties ◽

Triblock Copolymer ◽

Thermal Response ◽

Stimuli Responsive ◽

Self Assembling ◽

Polymeric Hydrogels ◽

Aba Triblock Copolymer ◽

Responsive Hydrogels

Directed self-assembly in polymeric hydrogels allows tunability of thermal response and viscoelastic properties.

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Structural and Technological Approach to Reveal the Role of the Lipid Phase in the Formation of Soy Emulsion Gels with Chia Oil

Gels ◽

10.3390/gels7020048 ◽

2021 ◽

Vol 7 (2) ◽

pp. 48

Author(s):

Ana M. Herrero ◽

Claudia Ruiz-Capillas

Keyword(s):

Raman Spectroscopy ◽

Structural Properties ◽

Structural Changes ◽

Protein Secondary Structure ◽

Lipid Phase ◽

Α Helix ◽

Β Sheet ◽

Shed Light ◽

Chia Oil

Considerable attention has been paid to emulsion gels (EGs) in recent years due to their interesting applications in food. The aim of this work is to shed light on the role played by chia oil in the technological and structural properties of EGs made from soy protein isolates (SPI) and alginate. Two systems were studied: oil-free SPI gels (SPI/G) and the corresponding SPI EGs (SPI/EG) that contain chia oil. The proximate composition, technological properties (syneresis, pH, color and texture) and structural properties using Raman spectroscopy were determined for SPI/G and SPI/EG. No noticeable (p > 0.05) syneresis was observed in either sample. The pH values were similar (p > 0.05) for SPI/G and SPI/EG, but their texture and color differed significantly depending on the presence of chia oil. SPI/EG featured significantly lower redness and more lightness and yellowness and exhibited greater puncture and gel strengths than SPI/G. Raman spectroscopy revealed significant changes in the protein secondary structure, i.e., higher (p < 0.05) α-helix and lower (p < 0.05) β-sheet, turn and unordered structures, after the incorporation of chia oil to form the corresponding SPI/EG. Apparently, there is a correlation between these structural changes and the textural modifications observed.

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