Stacking interactions by two Phe side chains stabilize and orient assemblies of even the minimal amphiphilic β-sheet motif

Zarzhitsky, Shlomo; Jelinek, Raz; Rapaport, Hanna

doi:10.1039/c4cc09673h

Cited by 28 publications

(30 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Second derivative analysis revealed additional peaks at 1624 and 1636 cm –1 . These peaks are indicative of a β-sheet secondary structure. , CD spectra showed peaks at 202 and 222 nm, corresponding to π–π* and n−π* transitions (Figure b). , These peaks were previously reported for phenylalanine-based compounds, such as FF and its analogs, and Phe-Glu-Phe. , …”

Section: Resultssupporting

confidence: 66%

“…CD spectra showed peaks at 202 and 222 nm, corresponding to π − π * and n− π * transitions (Figure 2b). 51,52 These peaks were previously reported for phenyl-alanine-based compounds, such as FF and its analogs, and Phe-Glu-Phe 22,53…”

Section: Resultssupporting

confidence: 55%

“…51,52 These peaks were previously reported for phenylalanine-based compounds, such as FF and its analogs, and Phe-Glu-Phe. 22,53 Hydrogel Rheology. As noted above, z-FF was found to form hydrogels when all stock solutions were diluted to a solution of 75−100% water, in all peptide concentrations (Figure 1f).…”

Section: Resultsmentioning

confidence: 99%

See 2 more Smart Citations

Structural Polymorphism in a Self-Assembled Tri-Aromatic Peptide System

et al. 2018

View full text Add to dashboard Cite

Self-assembly is a process of key importance in natural systems and in nanotechnology. Peptides are attractive building blocks due to their relative facile synthesis, biocompatibility, and other unique properties. Diphenylalanine (FF) and its derivatives are known to form nanostructures of various architectures and interesting and varied characteristics. The larger triphenylalanine peptide (FFF) was found to self-assemble as efficiently as FF, forming related but distinct architectures of plate-like and spherical nanostructures. Here, to understand the effect of triaromatic systems on the self-assembly process, we examined carboxybenzyl-protected diphenylalanine (z-FF) as a minimal model for such an arrangement. We explored different self-assembly conditions by changing solvent compositions and peptide concentrations, generating a phase diagram for the assemblies. We discovered that z-FF can form a variety of structures, including nanowires, fibers, nanospheres, and nanotoroids, the latter were previously observed only in considerably larger or co-assembly systems. Secondary structure analysis revealed that all assemblies possessed a β-sheet conformation. Additionally, in solvent combinations with high water ratios, z-FF formed rigid and self-healing hydrogels. X-ray crystallography revealed a "wishbone" structure, in which z-FF dimers are linked by hydrogen bonds mediated by methanol molecules, with a 2-fold screw symmetry along the c-axis. All-atom molecular dynamics (MD) simulations revealed conformations similar to the crystal structure. Coarse-grained MD simulated the assembly of the peptide into either fibers or spheres in different solvent systems, consistent with the experimental results. This work thus expands the building block library for the fabrication of nanostructures by peptide self-assembly.

show abstract

Section: Resultssupporting

confidence: 66%

Section: Resultssupporting

confidence: 55%

See 1 more Smart Citation

Structural Polymorphism in a Self-Assembled Tri-Aromatic Peptide System

et al. 2018

View full text Add to dashboard Cite

show abstract

“…In particular, we studied the effect of varying the sequence order as well as the side chain length of the lysine analog. In FF peptides and derivatives, various design rules have been reported to account for the importance of π–π stacking of the phenyl groups, interbackbone beta-sheet packing, and chirality. ,, Chirality and inter- and intra-backbone H-bonding are however absent in peptoids. Our designs therefore test the minimal requirements for nanostructure assembly of peptoids/peptides that are directly soluble in water.…”

mentioning

confidence: 99%

Self-Assembly of Minimal Peptoid Sequences

et al. 2020

View full text Add to dashboard Cite

Peptoids are biofunctional N-substituted glycine peptidomimics. Their self-assembly is of fundamental interest because they demonstrate alternatives to conventional peptide structures based on backbone chirality and beta-sheet hydrogen bonding. The search for self-assembling, water-soluble “minimal” sequences, be they peptide or peptidomimic, is a further challenge. Such sequences are highly desired for their compatibility with biomacromolecules and convenient synthesis for broader application. We report the self-assembly of a set of trimeric, water-soluble α-peptoids that exhibit a relatively low critical aggregation concentration (CAC ∼ 0.3 wt %). Cryo-EM and angle-resolved DLS show different sequence-dependent morphologies, namely uniform ca. 6 nm wide nanofibers, sheets, and clusters of globular assemblies. Absorbance and fluorescence spectroscopies indicate unique phenyl environments for π-interactions in the highly ordered nanofibers. Assembly of our peptoids takes place when the sequences are fully ionized, representing a departure from superficially similar amyloid-type hydrogen-bonded peptide nanostructures and expanding the horizons of assembly for sequence-specific bio- and biomimetic macromolecules.

show abstract

“…Such positive CD peaks, associated with stacking interactions between Phe side chains, were previously detected also by us for the peptide Phe-Glu-Phe at low peptide concentrations. 35–37 At higher peptide concentrations the CD spectra of this tripeptide transformed into the commonly detected spectra of β-sheet structures. Hence, CD spectra of FD and FD-RGD and their mixtures, exhibit similar conformations in solution, that enable coexisting Phe–Phe interactions along with generally unordered conformation, attributed to the negative absorption peak at 204 nm, that is expected at low concentration regions of such negatively charged peptides.…”

Section: Resultsmentioning

confidence: 96%