Subunit asymmetry in the three‐dimensional structure of a human CuZnSOD mutant found in familial amyotrophic lateral sclerosis

Hart, P. John; Liu, Hongbin; Pellegrini, Matteo; Nersissian, Aram M.; Gralla, Edith Butler; Valentine, Joan Selverstone; Eisenberg, David

doi:10.1002/pro.5560070302

Cited by 101 publications

(22 citation statements)

References 74 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Thus for G37R 64% of the residues are more flexible than the wild type with the highest flexibility computed for those helix-forming residues within the ESL. This correlates well with the dramatic subunit asymmetry observed in the G37R crystal structure, as well as with the higher crystallographic B-factors measured for those loop residues [29]. For the crystal structure of the ASU in 2ZKX the ESL residues 126–139 of subunit D, the dimer partner of the circled chain in Figure 1, are missing, also indicating significant disorder.…”

Section: Resultssupporting

confidence: 74%

See 1 more Smart Citation

A mechanism for propagated SOD1 misfolding from frustration analysis of a G85R mutant protein assembly

Healy

2016

Biochemical and Biophysical Research Communications

View full text Add to dashboard Cite

Application of landscape theory and the dehydron hypothesis to a crystal structure of a G85R mutant superoxide dismutase (SOD1) tetrameric complex allows for the description of a prion-like hypothesis that serves to explain propagated SOD1 misfolding. We have developed two conformational-change scenarios, one local to the ESL at the complex interface, and a second displacement at the ESL of the another dimeric subunit. When taken together these provide for a prion-like mechanism that can serve to explain the observed conversion of wtSOD1 to a misfolded form by the G85R mutant.

show abstract

Section: Resultssupporting

confidence: 74%

“…The crystal structures for wild type (wt), the G37R mutant, and the G85R mutant of human superoxide dismutase are available from the RCSB (www.rcsb.org) as PDB entries 2C9V [28], 1AZV [29], and 2ZKX respectively. After adding hydrogens all proteins were subjected to a short energy minimization using the CHARMm force field [30].…”

Section: Methodsmentioning

confidence: 99%

A mechanism for propagated SOD1 misfolding from frustration analysis of a G85R mutant protein assembly

Healy

2016

Biochemical and Biophysical Research Communications

View full text Add to dashboard Cite

show abstract

“…The correlation was relatively weak ( r 2 = 0.31), however when SOD1 G37R was omitted from the linear fit, the correlation became much stronger ( r 2 = 0.70). SOD1 G37R is a curious outlier as it is defined as “wild-type like” due to its structural similarities with SOD1 WT (Hart et al, 1998) and has a long variable disease duration of ~17 years (Wang et al, 2008), yet in our assays presents severe structural destabilization on similar levels as the aggressive SOD1 G93A and SOD1 V148G variants (~2.2 and ~2.3 years patient survival, respectively). Given that aggregation propensity did not very well predict cellular aggregation we next asked whether the relative abundance of destabilized monomer correlated with cellular aggregation (Figure 7D).…”

Section: Resultsmentioning

confidence: 92%

Susceptibility of Mutant SOD1 to Form a Destabilized Monomer Predicts Cellular Aggregation and Toxicity but Not In vitro Aggregation Propensity

2016

View full text Add to dashboard Cite

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by the rapid and progressive degeneration of upper and lower motor neurons in the spinal cord, brain stem and motor cortex. The first gene linked to ALS was the gene encoding the free radical scavenging enzyme superoxide dismutase-1 (SOD1) that currently has over 180, mostly missense, ALS-associated mutations identified. SOD1-associated fALS patients show remarkably broad mean survival times (<1 year to ~17 years death post-diagnosis) that are mutation dependent. A hallmark of SOD1-associated ALS is the deposition of SOD1 into large insoluble aggregates in motor neurons. This is thought to be a consequence of mutation induced structural destabilization and/or oxidative damage leading to the misfolding and aggregation of SOD1 into a neurotoxic species. Here we aim to understand the relationship between SOD1 variant toxicity, structural stability, and aggregation propensity using a combination of cell culture and purified protein assays. Cell based assays indicated that aggregation of SOD1 variants correlate closely to cellular toxicity. However, the relationship between cellular toxicity and disease severity was less clear. We next utilized mass spectrometry to interrogate the structural consequences of metal loss and disulfide reduction on fALS-associated SOD1 variant structure. All variants showed evidence of unfolded, intermediate, and compact conformations, with SOD1G37R, SOD1G93A and SOD1V148G having the greatest abundance of intermediate and unfolded SOD1. SOD1G37R was an informative outlier as it had a high propensity to unfold and form oligomeric aggregates, but it did not aggregate to the same extent as SOD1G93A and SOD1V148G in in vitro aggregation assays. Furthermore, seeding the aggregation of DTT/EDTA-treated SOD1G37R with preformed SOD1G93A fibrils elicited minimal aggregation response, suggesting that the arginine substitution at position-37 blocks the templating of SOD1 onto preformed fibrils. We propose that this difference may be explained by multiple strains of SOD1 aggregate and this may also help explain the slow disease progression observed in patients with SOD1G37R.

show abstract

“…The crystal structures for wild type (wt), the G37R mutant, and the metal-deficient H46R mutant of human superoxide dismutase are available from the RCSB (www.rcsb.org) as PDB entries 2C9V (Strange et al 2006), 1AZV (Hart et al 1998), and 1OZT (Elam et al 2003), respectively. Although the β-barrel core of the H46R mutant is preserved relative to wt SOD1, both the zinc and electrostatic loops exhibit significant disorder.…”

Section: Methodsmentioning

confidence: 99%

An in silico study of the effect of SOD1 electrostatic loop dynamics on amyloid‑like filament formation

Healy

Cervantes

2016

Eur Biophys J

View full text Add to dashboard Cite

Superoxide dismutase [Cu–Zn], or SOD1, is a homo-dimeric protein that functions as an antioxidant by scavenging for superoxides. A wide range of SOD1 variants are linked to inherited, or familial, amyotrophic lateral sclerosis, a progressive and fatal neurodegenerative disease. Aberrant SOD1 oligomerization has been strongly implicated in disease causation, even for sporadic ALS, or SALS, which accounts for ~90 % of ALS cases. Small heat shock proteins (sHSP) have been shown to protect against amyloid fibril formation in vitro, and the sHSP αB-crystallin suppresses in vitro aggregation of SOD1. We are seeking to elucidate the structural features of both SOD1 amyloid formation and αB-crystallin amyloid suppression. Specifically, we have used a flexible docking protocol to refine our model of a SOD1 non-obligate tetramer, postulated to function as a transient desolvating complex. Homology modeling and molecular dynamics (MD) are used to supply the missing structural elements of a previously characterized SOD1 amyloid filament, thereby providing a structural analysis for the observed gain of interaction. This completed filament is then further modified using MD to provide a structural model for protofibril capping of SOD1 filaments by αB-crystallin.

show abstract

Subunit asymmetry in the three‐dimensional structure of a human CuZnSOD mutant found in familial amyotrophic lateral sclerosis

Cited by 101 publications

References 74 publications

A mechanism for propagated SOD1 misfolding from frustration analysis of a G85R mutant protein assembly

A mechanism for propagated SOD1 misfolding from frustration analysis of a G85R mutant protein assembly

Susceptibility of Mutant SOD1 to Form a Destabilized Monomer Predicts Cellular Aggregation and Toxicity but Not In vitro Aggregation Propensity

An in silico study of the effect of SOD1 electrostatic loop dynamics on amyloid‑like filament formation

Contact Info

Product

Resources

About