ジャーナル: Nat Commun / 年: 2022 タイトル: pH- and concentration-dependent supramolecular assembly of a fungal defensin plectasin variant into helical non-amyloid fibrils. 著者: Christin Pohl / Gregory Effantin / Eaazhisai Kandiah / Sebastian Meier / Guanghong Zeng / Werner Streicher / Dorotea Raventos Segura / Per H Mygind / Dorthe Sandvang / Line Anker Nielsen / ...著者: Christin Pohl / Gregory Effantin / Eaazhisai Kandiah / Sebastian Meier / Guanghong Zeng / Werner Streicher / Dorotea Raventos Segura / Per H Mygind / Dorthe Sandvang / Line Anker Nielsen / Günther H J Peters / Guy Schoehn / Christoph Mueller-Dieckmann / Allan Noergaard / Pernille Harris / 要旨: Self-assembly and fibril formation play important roles in protein behaviour. Amyloid fibril formation is well-studied due to its role in neurodegenerative diseases and characterized by refolding of ...Self-assembly and fibril formation play important roles in protein behaviour. Amyloid fibril formation is well-studied due to its role in neurodegenerative diseases and characterized by refolding of the protein into predominantly β-sheet form. However, much less is known about the assembly of proteins into other types of supramolecular structures. Using cryo-electron microscopy at a resolution of 1.97 Å, we show that a triple-mutant of the anti-microbial peptide plectasin, PPI42, assembles into helical non-amyloid fibrils. The in vitro anti-microbial activity was determined and shown to be enhanced compared to the wildtype. Plectasin contains a cysteine-stabilised α-helix-β-sheet structure, which remains intact upon fibril formation. Two protofilaments form a right-handed protein fibril. The fibril formation is reversible and follows sigmoidal kinetics with a pH- and concentration dependent equilibrium between soluble monomer and protein fibril. This high-resolution structure reveals that α/β proteins can natively assemble into fibrils.