Related Experiment Video
Updated: Feb 7, 2026
07:26
Formation of Ordered Biomolecular Structures by the Self-assembly of Short Peptides
Published on: November 21, 2013
13.4K
Designed peptides that assemble into cross-α amyloid-like structures.
Shao-Qing Zhang1,2,3, Hai Huang3, Junjiao Yang2,3
1Department of Chemistry, University of Pennsylvania, Philadelphia, PA, USA.
Nature Chemical Biology
|August 1, 2018
Summary
Researchers designed peptides that form novel cross-alpha (cross-α) amyloid-like fibrils, mimicking twisted beta-amyloid structures. These self-assembling peptides offer potential for controlling protein structures in biological systems.
Area of Science:
- Biochemistry
- Structural Biology
- Biophysics
Background:
- Amyloids are known for their cross-beta (cross-β) fibril structures.
- Recent studies proposed amyloid-like cross-alpha (cross-α) structures.
Purpose of the Study:
- To crystallographically characterize designed peptides forming cross-α amyloid-like structures.
- To investigate the self-assembly and structural properties of novel amyloid mimics.
Main Methods:
- X-ray crystallography to determine peptide structures.
- Peptide design and synthesis.
- Fluorescence microscopy to observe cellular localization and dynamics.
Main Results:
- Designed peptides self-assembled into spiraling cross-α amyloid-like fibrils.
- Fibrils exhibited superhelical pitches between 170-200 Å.
- Mutating a key residue induced a structural shift to helical polymers.
- Cellular studies showed punctate structures with distinct photobleaching recovery kinetics.
Conclusions:
- Demonstrated the feasibility of designing peptides that form cross-α amyloid-like fibrils.
- Identified key residues influencing self-assembly pathways.
- Highlighted the potential of these structures for directed in vivo protein assembly with controlled spacing and stability.
Related Concept Videos
03:03Amyloid Fibrils
12.0K
Amyloid fibrils are aggregates of misfolded proteins. Under most circumstances, misfolded proteins are either refolded by chaperone proteins or degraded by the proteasome. However, in the case of a mutation or a disease, these proteins can accumulate to form large clusters and often further assemble to form elongated fibers, called fibrils.
Amyloid deposits were observed as early as 1639 in the liver and the spleen. In 1854, Rudolph Virchow performed iodine staining,...
Amyloid deposits were observed as early as 1639 in the liver and the spleen. In 1854, Rudolph Virchow performed iodine staining,...
12.0K
02:15Protein and Protein Structure
88.2K
Proteins are one of the most abundant organic molecules in living systems and have the most diverse range of functions of all macromolecules. Proteins may be structural, regulatory, contractile, or protective. They may serve in transport, storage, or membranes; or they may be toxins or enzymes. Their structures, like their functions, vary greatly. They are all, however, amino acid polymers arranged in a linear sequence.
A protein's shape is critical to its function. For example, an enzyme...
A protein's shape is critical to its function. For example, an enzyme...
88.2K
01:32Assembly of Complex Microtubule Structures
2.5K
Complex microtubule structures are present in resting cells and in dividing cells. In resting cells, they are responsible for maintaining the cellular architecture, tracks for intracellular transport, positioning of organelles, assembly of cilia and flagella. They mediate the bipolar spindle assembly for chromosomal segregation and positioning of the cell division plate in dividing cells. The formation of microtubule complex structures depends on the cell type, cell stage, and cell function.
2.5K
02:43Peptide Bonds
83.2K
A peptide bond covalently attaches amino acids through a dehydration reaction. One amino acid's carboxyl group and another amino acid's amino group combine, releasing a water molecule. The resulting bond is the peptide bond. The products that such linkages form are peptides. As more amino acids join this growing chain, the resulting chain is a polypeptide. Each polypeptide has a free amino group at one end. This end has the N-terminal, or the amino-terminal, and the other end has a free...
83.2K
01:34Crossing Over
172.1K
Unlike mitosis, meiosis aims for genetic diversity in its creation of haploid gametes. Dividing germ cells first begin this process in prophase I, where each chromosome—replicated in S phase—is now composed of two sister chromatids (identical copies) joined centrally.
The homologous pairs of sister chromosomes—one from the maternal and one from the paternal genome—then begin to align alongside each other lengthwise, matching corresponding DNA positions in a process...
The homologous pairs of sister chromosomes—one from the maternal and one from the paternal genome—then begin to align alongside each other lengthwise, matching corresponding DNA positions in a process...
172.1K
01:28Structure-Activity Relationships and Drug Design
1.8K
Drug design is a dynamic field that involves discovering and developing new medications based on specific biological targets. This process heavily relies on structure-activity relationships (SAR) and quantitative structure-activity relationships (QSAR) to guide the design and optimization of efficient drugs.
SAR studies the intricate relationship between a drug's chemical structure and biological activity. It focuses on understanding how modifications to a drug's structure can influence...
SAR studies the intricate relationship between a drug's chemical structure and biological activity. It focuses on understanding how modifications to a drug's structure can influence...
1.8K