Glycerolipid Headgroups Control Rate and Mechanism of Superoxide Dismutase-1 Aggregation and Accelerate Fibrillization of Slowly Aggregating Amyotrophic Lateral Sclerosis Mutants

Rasouli, Sanaz; Abdolvahabi, Alireza; Croom, Corbin M.; Plewman, Devon L.; Shi, Yulei; Shaw, Bryan F.

doi:10.1021/acschemneuro.8b00086

Cited by 4 publications

(4 citation statements)

References 63 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Previous studies have shown that the stochastic fibrillization of SOD1 not only manifests in variation in observed lag time and propagation rate but also in the maximal ThT fluorescence reached during an iterate assay. , In this study, and previous studies, , the maximum ThT fluorescence of iterate assays of unseeded WT fibrillization varied 10-fold from well to well, typically ranging from 40 to 400 A.U. (Figures B, , and ).…”

Section: Results and Discussionsupporting

confidence: 70%

“…Approximately 2% of cases of amyotrophic lateral sclerosis (ALS) are caused by >160 different mutations in the gene encoding Cu, Zn superoxide dismutase (SOD1), a homodimeric enzyme. − Most mutations have an autosomal dominant mode of inheritance, resulting in heterozygous individuals. The self-assembly of mutant and wild-type (WT) forms of SOD1 into amyloid-like oligomers is hypothesized to trigger ALS pathogenesis via a prion-like mechanism. − Measuring the rate of self-assembly of WT and ALS mutant SOD1 into amyloid-like speciesand doing so reliably and reproduciblyis important for: (i) understanding whether mutations induce toxicity by altering intrinsic rates of self-assembly , or interactions with other proteins − or membrane surfaces − and (ii) discovering agents that inhibit or detoxify SOD1 aggregation.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Kinetic Variability in Seeded Formation of ALS-Linked SOD1 Fibrils Across Multiple Generations

Baumer

Koone

Shaw

2020

ACS Chem. Neurosci.

Self Cite

View full text Add to dashboard Cite

The unseeded aggregation of superoxide dismutase-1 (SOD1) into amyloid-like fibrils occurs stochastically in vitro and in vivo, that is, isolated populations of SOD1 proteins (within microplate wells or living cells) self-assemble into amyloid at rates that span a probability distribution. This stochasticity has been attributed to variable degrees of monomer depletion by competing pathways of amorphous and fibrillar aggregation (inter alia). Here, microplate-based thioflavin-T (ThT) fluorescence assays were performed at high iteration (∼300) to establish whether this observed stochasticity persists when progenitor (“parent”) SOD1 fibrils are used to seed the formation of multiple generations of progeny fibrils (daughter, granddaughter, and great-granddaughter fibrils). Populations of progenitor fibrils formed stochastically at different rates and fluorescence intensity, however, progeny fibrils formed at more similar rates regardless of the formation rate of the progenitor fibril. For example, populations of progenitor fibrils that formed with a lag time of ∼30 h or ∼15 h both produced progeny fibrils with lag times of ∼8 h. Likewise, populations of progenitor fibrils with high or low maximum fluorescence (e.g., ∼450 or ∼75 A.U.) both produced progeny fibrils with more similar maximum fluorescence (∼125 A.U.). The rate of propagation was found to be more dependent on monomer concentration than seed concentration. These results can be rationalized by classical rate laws for primary nucleation and monomer-dependent secondary nucleation. We also find that the seeding propensity of some “families” of in vitro grown fibrils exhibit a finite lifetime (similar to that observed in the seeding of small molecule crystals and colloids). The single biological takeaway of this study is that the concentration of native SOD1 in a cell can have a stronger effect on rates of seeded aggregation than the concentration of prion-like seed that infected the cell.

show abstract

Section: Results and Discussionsupporting

confidence: 70%

Section: Introductionmentioning

confidence: 99%

Kinetic Variability in Seeded Formation of ALS-Linked SOD1 Fibrils Across Multiple Generations

Baumer

Koone

Shaw

2020

ACS Chem. Neurosci.

Self Cite

View full text Add to dashboard Cite

show abstract

“…When incubated with phospholipids, Rasouli et al . (2018) found SOD1 aggregation was influenced by the charge of the head group, lipid concentration and the SOD1 variant. For example, anionic phospholipids greatly stimulated metal-free wild-type SOD1 fibril formation over a broad range of concentrations whereas zwitterionic did not.…”

Section: Sod1 Aggregation In Alsmentioning

confidence: 99%

The biophysics of superoxide dismutase-1 and amyotrophic lateral sclerosis

Wright

Antonyuk

Hasnain

2019

Quart. Rev. Biophys.

View full text Add to dashboard Cite

Few proteins have come under such intense scrutiny as superoxide dismutase-1 (SOD1). For almost a century, scientists have dissected its form, function and then later its malfunction in the neurodegenerative disease amyotrophic lateral sclerosis (ALS). We now know SOD1 is a zinc and copper metalloenzyme that clears superoxide as part of our antioxidant defence and respiratory regulation systems. The possibility of reduced structural integrity was suggested by the first crystal structures of human SOD1 even before deleterious mutations in thesod1gene were linked to the ALS. This concept evolved in the intervening years as an impressive array of biophysical studies examined the characteristics of mutant SOD1 in great detail. We now recognise how ALS-related mutations perturb the SOD1 maturation processes, reduce its ability to fold and reduce its thermal stability and half-life. Mutant SOD1 is therefore predisposed to monomerisation, non-canonical self-interactions, the formation of small misfolded oligomers and ultimately accumulation in the tell-tale insoluble inclusions found within the neurons of ALS patients. We have also seen that several post-translational modifications could push wild-type SOD1 down this toxic pathway. Recently we have come to view ALS as a prion-like disease where both the symptoms, and indeed SOD1 misfolding itself, are transmitted to neighbouring cells. This raises the possibility of intervention after the initial disease presentation. Several small-molecule and biologic-based strategies have been devised which directly target the SOD1 molecule to change the behaviour thought to be responsible for ALS. Here we provide a comprehensive review of the many biophysical advances that sculpted our view of SOD1 biology and the recent work that aims to apply this knowledge for therapeutic outcomes in ALS.

show abstract

“…The ability of S-XL6 to diminish aggregates is expected based upon S-XL6-mediated stabilization of SOD1 variants, given that stabilization increases the time required for the nucleation phase of aggregation. We are currently unable to measure the rates of aggregation because existing assays require reductants that would also remove S-XL6 [38,39]. peptide (purple) linked by S-XL6.…”

Section: Structural Analysis Of S-xl6 Cross-linked Fals Sod1 Variantsmentioning

confidence: 99%

Evaluating protein cross-linking as a therapeutic strategy to stabilize SOD1 variants in a mouse model of familial ALS

Hossain,

Sarin,

Donnelly

et al. 2024

PLoS Biol

View full text Add to dashboard Cite

Mutations in the gene encoding Cu-Zn superoxide dismutase 1 (SOD1) cause a subset of familial amyotrophic lateral sclerosis (fALS) cases. A shared effect of these mutations is that SOD1, which is normally a stable dimer, dissociates into toxic monomers that seed toxic aggregates. Considerable research effort has been devoted to developing compounds that stabilize the dimer of fALS SOD1 variants, but unfortunately, this has not yet resulted in a treatment. We hypothesized that cyclic thiosulfinate cross-linkers, which selectively target a rare, 2 cysteine-containing motif, can stabilize fALS-causing SOD1 variants in vivo. We created a library of chemically diverse cyclic thiosulfinates and determined structure-cross-linking-activity relationships. A pre-lead compound, “S-XL6,” was selected based upon its cross-linking rate and drug-like properties. Co-crystallographic structure clearly establishes the binding of S-XL6 at Cys 111 bridging the monomers and stabilizing the SOD1 dimer. Biophysical studies reveal that the degree of stabilization afforded by S-XL6 (up to 24°C) is unprecedented for fALS, and to our knowledge, for any protein target of any kinetic stabilizer. Gene silencing and protein degrading therapeutic approaches require careful dose titration to balance the benefit of diminished fALS SOD1 expression with the toxic loss-of-enzymatic function. We show that S-XL6 does not share this liability because it rescues the activity of fALS SOD1 variants. No pharmacological agent has been proven to bind to SOD1 in vivo. Here, using a fALS mouse model, we demonstrate oral bioavailability; rapid engagement of SOD1G93A by S-XL6 that increases SOD1G93A’s in vivo half-life; and that S-XL6 crosses the blood–brain barrier. S-XL6 demonstrated a degree of selectivity by avoiding off-target binding to plasma proteins. Taken together, our results indicate that cyclic thiosulfinate-mediated SOD1 stabilization should receive further attention as a potential therapeutic approach for fALS.

show abstract

Glycerolipid Headgroups Control Rate and Mechanism of Superoxide Dismutase-1 Aggregation and Accelerate Fibrillization of Slowly Aggregating Amyotrophic Lateral Sclerosis Mutants

Cited by 4 publications

References 63 publications

Kinetic Variability in Seeded Formation of ALS-Linked SOD1 Fibrils Across Multiple Generations

Kinetic Variability in Seeded Formation of ALS-Linked SOD1 Fibrils Across Multiple Generations

The biophysics of superoxide dismutase-1 and amyotrophic lateral sclerosis

Evaluating protein cross-linking as a therapeutic strategy to stabilize SOD1 variants in a mouse model of familial ALS

Contact Info

Product

Resources

About