Abstract

Amyloidogenesis is associated with more than 30 diseases, but the molecular mechanisms involved in cell toxicity and fibril formation remain largely unknown. The inherent tendency of amyloid-forming proteins to aggregate renders expression, purification, and experimental studies challenging. NT* is a solubility tag derived from a spider silk protein that was recently introduced for the production of several aggregation-prone peptides and proteins at high yields. Herein, we investigate whether fusion to NT* can prevent amyloid fibril formation and enable controlled aggregation for experimental studies. As an example of an amyloidogenic protein, we chose the de novo-designed polypeptide 17. The fusion protein NT*-17 was recombinantly expressed in Escherichia coli to produce high amounts of soluble and mostly monomeric protein. Structural analysis showed that 17 is kept in a largely unstructured conformation in fusion with NT*. After proteolytic release, 17 adopts a -sheet conformation in a pH- and salt-dependent manner and assembles into amyloid-like fibrils. The ability of NT* to prevent premature aggregation and to enable structural studies of prefibrillar states may facilitate investigation of proteins involved in amyloid diseases.

Keywords

amyloid disease; fibril formation; model protein; protein assembly; protein domain

Published in

FEBS Journal
2018, Volume: 285, number: 10, pages: 1873-1885
Publisher: WILEY

SLU Authors

• Rising, Anna

  • Department of Animal Biosciences, Swedish University of Agricultural Sciences
    
  • Karolinska Institute

UKÄ Subject classification

Biochemistry and Molecular Biology


Publication identifier

DOI: https://doi.org/10.1111/febs.14451

Permanent link to this page (URI)

https://res.slu.se/id/publ/95808