Related Experiment Video
Updated: Jun 19, 2025
07:26
Formation of Ordered Biomolecular Structures by the Self-assembly of Short Peptides
Published on: November 21, 2013
12.9K
Chiral inversion induced by aromatic interactions in short peptide assembly
Kai Qi1, Hao Qi1, Muhan Wang2
1State Key Laboratory of Heavy Oil Processing and Department of Biological and Energy Chemical Engineering, China University of Petroleum (East China), 66 Changjiang West Road, Qingdao, 266580, China.
Nature Communications
|July 23, 2024
Summary
Hydrophobic interactions influence peptide self-assembly. Aromatic side chains dictate suprastructure handedness by directing beta-strand twisting and aromatic ladder formation in peptide amphiphiles.
Area of Science:
- Supramolecular chemistry
- Biomaterials science
- Chemical biology
Background:
- Hydrophobic interactions are key drivers of initial peptide aggregation.
- The role of these interactions in determining the handedness of higher-order peptide suprastructures is not well understood.
Purpose of the Study:
- To investigate how hydrophobic amino acid side chains influence the handedness of peptide amphiphile assemblies.
- To explore the effects at different stages of self-assembly.
Main Methods:
- Systematic interrogation of peptide amphiphiles with varying hydrophobic side chains (aliphatic vs. aromatic).
- Analysis of self-assembly stages from single beta-strands to multi-stranded beta-sheets.
- Characterization of suprastructure formation and handedness.
Main Results:
- Aromatic side chains, unlike aliphatic ones, induce specific twisting in beta-strands due to steric repulsion.
- Interactions between aromatic side chains lead to directional 'aromatic ladders' during beta-sheet formation.
- This directional ordering promotes parallel beta-sheet arrangements and chiral flipping of beta-strands within sheets.
- Aliphatic peptides lack these orientational hydrophobic interactions, showing no chiral inversion upon beta-sheet packing.
Conclusions:
- Aromatic side-chain interactions are critical determinants of suprastructure handedness in peptide amphiphiles.
- Understanding these interactions allows for the targeted design of peptide aggregates with specific chirality.
- This research opens new possibilities for controlling the higher-order structure of peptide-based materials.
More Related Videos
Related Concept Videos
02:30Chirality in Nature
13.3K
Chirality is the most intriguing yet essential facet of nature, governing life’s biochemical processes and precision. It can be observed from a snail shell pattern in a macroscopic world to an amino acid, the minutest building block of life. Most of the snails around the world have right-coiled shells because of the intrinsic chirality in their genes. All the amino acids present in the human body exist in an enantiomerically pure state, except for glycine - the sole achiral amino acid.
13.3K
02:05Prochirality
3.8K
The concept of prochirality leads to the nomenclature of the individual faces of a molecule and plays a crucial role in the enantioselective reaction. It is a concept where two or more achiral molecules react to produce chiral products. A typical process is the reaction of an achiral ketone to generate a chiral alcohol. Here, the achiral reactant reacts with an achiral reducing agent, sodium borohydride, to generate an equimolar mixture of the chiral enantiomers of the product. For example, an...
3.8K
02:30Chirality at Nitrogen, Phosphorus, and Sulfur
5.7K
Chirality is most prevalent in carbon-based tetrahedral compounds, but this important facet of molecular symmetry extends to sp3-hybridized nitrogen, phosphorus and sulfur centers, including trivalent molecules with lone pairs. Here, the lone pair behaves as a functional group in addition to the other three substituents to form an analogous tetrahedral center that can be chiral.
A consequence of chirality is the need for enantiomeric resolution. While this is theoretically possible for all...
A consequence of chirality is the need for enantiomeric resolution. While this is theoretically possible for all...
5.7K
02:15SN1 Reaction: Stereochemistry
8.4K
This lesson provides an in-depth discussion of the stereochemical outcomes in an SN1 reaction.
In the first step of an SN1 reaction, the bond between the electrophilic carbon and the leaving group ionizes to generate the carbocation intermediate. The second step of the mechanism is the nucleophilic attack.
In the formed carbocation, the positively charged carbon is sp2 hybridized with a trigonal planar geometry. As all the three substituents lie on the same plane, a plane of symmetry for the...
In the first step of an SN1 reaction, the bond between the electrophilic carbon and the leaving group ionizes to generate the carbocation intermediate. The second step of the mechanism is the nucleophilic attack.
In the formed carbocation, the positively charged carbon is sp2 hybridized with a trigonal planar geometry. As all the three substituents lie on the same plane, a plane of symmetry for the...
8.4K
02:23SN2 Reaction: Stereochemistry
9.4K
In an SN2 reaction, the nucleophilic attack on the substrate and departure of the leaving group occurs simultaneously through a transition state. As the nucleophile approaches the substrate from the back-side, the configuration of the substrate carbon changes from tetrahedral to trigonal bipyramidal and then back to tetrahedral, leading to an inversion in the configuration of the product.
If the substrate is an achiral molecule at the α-carbon, the inversion of configuration is not...
If the substrate is an achiral molecule at the α-carbon, the inversion of configuration is not...
9.4K
01:19Structure of Amines
2.5K
The hybridized nitrogen atom in amines possesses a lone pair of electrons and is bound to three substituents with a bond angle of around 108°, which is less than the tetrahedral angle of 109.5°. However, the C–N–H bond angle is slightly larger at 112°, with a carbon–nitrogen bond length of 147 pm. This carbon–nitrogen bond length of of amines is longer than the carbon–oxygen bond of alcohols (143 pm) but shorter than alkanes’...
2.5K