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Publication Abstract from PubMed

The assembly of proteins into fibrillar amyloid structures was once considered to be pathologic and essentially irreversible. Recent studies reveal amyloid-like structures that form reversibly, derived from protein low-complexity domains which function in cellular metabolism. Here, by comparing atomic-level structures of reversible and irreversible amyloid fibrils, we find that the beta-sheets of reversible fibrils are enriched in flattened (as opposed to pleated) beta-sheets formed by stacking of extended beta-strands. Quantum mechanical calculations show that glycine residues favor extended beta-strands which may be stabilized by intraresidue interactions between the amide proton and the carbonyl oxygen, known as C5 hydrogen-bonds. Larger residue side chains favor shorter strands and pleated sheets. These findings highlight a structural element that may regulate reversible amyloid assembly.

Extended beta-Strands Contribute to Reversible Amyloid Formation.,Murray KA, Evans D, Hughes MP, Sawaya MR, Hu CJ, Houk KN, Eisenberg D ACS Nano. 2022 Feb 8. doi: 10.1021/acsnano.1c08043. PMID:35132852^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.