Orientation of aromatic residues in amyloid cores: Structural insights into prion fiber diversity
Artikel i vetenskaplig tidskrift, 2014

Structural conversion of one given protein sequence into different amyloid states, resulting in distinct phenotypes, is one of the most intriguing phenomena of protein biology. Despite great efforts the structural origin of prion diversity remains elusive, mainly because amyloids are insoluble yet noncrystalline and therefore not easily amenable to traditional structural-biology methods. We investigate two different phenotypic prion strains, weak and strong, of yeast translation termination factor Sup35 with respect to angular orientation of tyrosines using polarized light spectroscopy. By applying a combination of alignment methods the degree of fiber orientation can be assessed, which allows a relatively accurate determination of the aromatic ring angles. Surprisingly, the strains show identical average orientations of the tyrosines, which are evenly spread through the amyloid core. Small variations between the two strains are related to the local environment of a fraction of tyrosines outside the core, potentially reflecting differences in fibril packing.

polarized light

tyrosine

prion proteins

Sup35 strains

linear dichroism

Författare

Anna Reymer

Chalmers, Kemi- och bioteknik, Fysikalisk kemi

K. K. Frederick

Howard Hughes Medical Institute

Whitehead Institute for Biomedical Research

Sandra Rocha

Chalmers, Kemi- och bioteknik, Fysikalisk kemi

Tamas Beke-Somfai

Chalmers, Kemi- och bioteknik, Fysikalisk kemi

Catherine Kitts

Chalmers, Kemi- och bioteknik, Fysikalisk kemi

S. Lindquist

Massachusetts Institute of Technology (MIT)

Howard Hughes Medical Institute

Whitehead Institute for Biomedical Research

Bengt Nordén

Chalmers, Kemi- och bioteknik, Fysikalisk kemi

Proceedings of the National Academy of Sciences of the United States of America

0027-8424 (ISSN) 1091-6490 (eISSN)

Vol. 111 17158-17163

Ämneskategorier

Fysikalisk kemi

DOI

10.1073/pnas.1415663111