Biophysical characterization of p53 core domain aggregates

© 2020 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society..

Aggregation is the cause of numerous protein conformation diseases. A common facet of these maladies is the transition of a protein from its functional native state into higher order forms, such as oligomers and amyloid fibrils. p53 is an essential tumor suppressor that is prone to such conformational transitions, resulting in its compromised ability to avert cancer. This work explores the biophysical properties of early-, mid-, and late-stage p53 core domain (p53C) aggregates. Atomistic and coarse-grained molecular dynamics (MD) simulations suggest that early- and mid-stage p53C aggregates have a polymorphic topology of antiparallel and parallel β-sheets that localize to the core amyloidogenic sequence. Both topologies involve similar extents of interstrand mainchain hydrogen bonding, while sidechain interactions could play a role in regulating strand orientation. The free energy difference between the antiparallel and parallel states was within statistical uncertainty. Negative stain electron microscopy of mature fibrils shows a wide distribution of fiber widths, indicating that polymorphism may extend to the quaternary structure level. Circular dichroism of the fibrils was indicative of β-sheet rich structures in atypical conformations. The Raman spectrum of aggregated p53C was consistent with a mixture of arranged β-sheets and heterogeneous structural elements, which is compatible with the MD findings of an ordered β-sheet nucleus flanked by disordered structure. Structural polymorphism is a common property of amyloids; however, because certain polymorphs of the same protein can be more harmful than others, going forward it will be pertinent to establish correlations between p53C aggregate structure and pathology.

Medienart:

E-Artikel

Erscheinungsjahr:

2020

Erschienen:

2020

Enthalten in:

Zur Gesamtaufnahme - volume:477

Enthalten in:

The Biochemical journal - 477(2020), 1 vom: 17. Jan., Seite 111-120

Sprache:

Englisch

Beteiligte Personen:

Lima, Igor [VerfasserIn]
Navalkar, Ambuja [VerfasserIn]
Maji, Samir K [VerfasserIn]
Silva, Jerson L [VerfasserIn]
de Oliveira, Guilherme A P [VerfasserIn]
Cino, Elio A [VerfasserIn]

Links:

Volltext

Themen:

Aggregation
Amyloid
Cancer
Journal Article
P53
Protein Aggregates
Research Support, Non-U.S. Gov't
Tumor Suppressor Protein p53

Anmerkungen:

Date Completed 13.07.2020

Date Revised 13.07.2020

published: Print

Citation Status MEDLINE

doi:

10.1042/BCJ20190778

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM304421529