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Transient structural distortion of metal-free Cu/Zn superoxide dismutase triggers aberrant oligomerization.

Teilum, Kaare LU ; Smith, Melanie LU ; Schulz, Eike ; Christensen, Lea C ; Solomentsev, Gleb LU ; Oliveberg, Mikael and Akke, Mikael LU orcid (2009) In Proceedings of the National Academy of Sciences 106(43). p.18273-18278
Abstract
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease linked to the misfolding of Cu/Zn superoxide dismutase (SOD1). ALS-related defects in SOD1 result in a gain of toxic function that coincides with aberrant oligomerization. The structural events triggering oligomerization have remained enigmatic, however, as is the case in other protein-misfolding diseases. Here, we target the critical conformational change that defines the earliest step toward aggregation. Using nuclear spin relaxation dispersion experiments, we identified a short-lived (0.4 ms) and weakly populated (0.7%) conformation of metal-depleted SOD1 that triggers aberrant oligomerization. This excited state emanates from the folded ground state and is suppressed by... (More)
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease linked to the misfolding of Cu/Zn superoxide dismutase (SOD1). ALS-related defects in SOD1 result in a gain of toxic function that coincides with aberrant oligomerization. The structural events triggering oligomerization have remained enigmatic, however, as is the case in other protein-misfolding diseases. Here, we target the critical conformational change that defines the earliest step toward aggregation. Using nuclear spin relaxation dispersion experiments, we identified a short-lived (0.4 ms) and weakly populated (0.7%) conformation of metal-depleted SOD1 that triggers aberrant oligomerization. This excited state emanates from the folded ground state and is suppressed by metal binding, but is present in both the disulfide-oxidized and disulfide-reduced forms of the protein. Our results pinpoint a perturbed region of the excited-state structure that forms intermolecular contacts in the earliest nonnative dimer/oligomer. The conformational transition that triggers oligomerization is a common feature of WT SOD1 and ALS-associated mutants that have widely different physicochemical properties. But compared with WT SOD1, the mutants have enhanced structural distortions in their excited states, and in some cases slightly higher excited-state populations and lower kinetic barriers, implying increased susceptibility to oligomerization. Our results provide a unified picture that highlights both (i) a common denominator among different SOD1 variants that may explain why diverse mutations cause the same disease, and (ii) a structural basis that may aid in understanding how different mutations affect disease propensity and progression. (Less)
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author
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organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Proceedings of the National Academy of Sciences
volume
106
issue
43
pages
18273 - 18278
publisher
National Academy of Sciences
external identifiers
  • wos:000271222500043
  • pmid:19828437
  • scopus:70849113863
  • pmid:19828437
ISSN
1091-6490
DOI
10.1073/pnas.0907387106
language
English
LU publication?
yes
id
22eeba98-b7ec-4426-8b9d-514c6ce8e598 (old id 1500342)
date added to LUP
2016-04-01 12:21:05
date last changed
2022-03-13 08:45:01
@article{22eeba98-b7ec-4426-8b9d-514c6ce8e598,
  abstract     = {{Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease linked to the misfolding of Cu/Zn superoxide dismutase (SOD1). ALS-related defects in SOD1 result in a gain of toxic function that coincides with aberrant oligomerization. The structural events triggering oligomerization have remained enigmatic, however, as is the case in other protein-misfolding diseases. Here, we target the critical conformational change that defines the earliest step toward aggregation. Using nuclear spin relaxation dispersion experiments, we identified a short-lived (0.4 ms) and weakly populated (0.7%) conformation of metal-depleted SOD1 that triggers aberrant oligomerization. This excited state emanates from the folded ground state and is suppressed by metal binding, but is present in both the disulfide-oxidized and disulfide-reduced forms of the protein. Our results pinpoint a perturbed region of the excited-state structure that forms intermolecular contacts in the earliest nonnative dimer/oligomer. The conformational transition that triggers oligomerization is a common feature of WT SOD1 and ALS-associated mutants that have widely different physicochemical properties. But compared with WT SOD1, the mutants have enhanced structural distortions in their excited states, and in some cases slightly higher excited-state populations and lower kinetic barriers, implying increased susceptibility to oligomerization. Our results provide a unified picture that highlights both (i) a common denominator among different SOD1 variants that may explain why diverse mutations cause the same disease, and (ii) a structural basis that may aid in understanding how different mutations affect disease propensity and progression.}},
  author       = {{Teilum, Kaare and Smith, Melanie and Schulz, Eike and Christensen, Lea C and Solomentsev, Gleb and Oliveberg, Mikael and Akke, Mikael}},
  issn         = {{1091-6490}},
  language     = {{eng}},
  number       = {{43}},
  pages        = {{18273--18278}},
  publisher    = {{National Academy of Sciences}},
  series       = {{Proceedings of the National Academy of Sciences}},
  title        = {{Transient structural distortion of metal-free Cu/Zn superoxide dismutase triggers aberrant oligomerization.}},
  url          = {{http://dx.doi.org/10.1073/pnas.0907387106}},
  doi          = {{10.1073/pnas.0907387106}},
  volume       = {{106}},
  year         = {{2009}},
}