6C4X

Cross-alpha Amyloid-like Structure alphaAmmem

Summary for 6C4X

• Entry DOI: 10.2210/pdb6c4x/pdb
• Descriptor: cross-alpha amyloid-like membrane peptide alpha-AmMEM, (4S)-2-METHYL-2,4-PENTANEDIOL, ZINC ION, ... (4 entities in total)
• Functional Keywords: protein design, cross-alpha amyloid, de novo protein
• Biological source: synthetic construct
• Total number of polymer chains: 8
• Total formula weight: 22780.55

Authors

Liu, L.,Zhang, S.Q. (deposition date: 2018-01-13, release date: 2018-08-15, Last modification date: 2024-10-30)

Primary citation

Zhang, S.Q.,Huang, H.,Yang, J.,Kratochvil, H.T.,Lolicato, M.,Liu, Y.,Shu, X.,Liu, L.,DeGrado, W.F.
Designed peptides that assemble into cross-alpha amyloid-like structures.
Nat. Chem. Biol., 14:870-875, 2018

PubMed Abstract: Amyloids adopt 'cross-β' structures composed of long, twisted fibrils with β-strands running perpendicular to the fibril axis. Recently, a toxic peptide was proposed to form amyloid-like cross-α structures in solution, with a planar bilayer-like assembly observed in the crystal structure. Here we crystallographically characterize designed peptides that assemble into spiraling cross-α amyloid-like structures, which resemble twisted β-amyloid fibrils. The peptides form helical dimers, stabilized by packing of small and apolar residues, and the dimers further assemble into cross-α amyloid-like fibrils with superhelical pitches ranging from 170 Å to 200 Å. When a small residue that appeared critical for packing was converted to leucine, it resulted in structural rearrangement to a helical polymer. Fluorescently tagged versions of the designed peptides form puncta in mammalian cells, which recover from photobleaching with markedly different kinetics. These structural folds could be potentially useful for directing in vivo protein assemblies with predetermined spacing and stabilities.

PubMed: 30061717
DOI: 10.1038/s41589-018-0105-5

Experimental method

X-RAY DIFFRACTION (3.55 Å)