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Ligand binding and aggregation of pathogenic SOD1.

Wright GS, Antonyuk SV, Kershaw NM, Strange RW, Samar Hasnain S - Nat Commun (2013)

Bottom Line: Superoxide dismutase-1 mutations decrease protein stability and promote aggregation.We find both compounds interact with superoxide dismutase-1 at a key region identified at the core of the superoxide dismutase-1 fibrillar aggregates, β-barrel loop II-strand 3, rather than the proposed dimer interface site.This illustrates the need for direct structural observations when developing compounds for protein-targeted therapeutics.

View Article: PubMed Central - PubMed

Affiliation: Molecular Biophysics Group, Institute of Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Liverpool L69 7ZB, UK.

ABSTRACT
Mutations in the gene encoding Cu/Zn superoxide dismutase-1 cause amyotrophic lateral sclerosis. Superoxide dismutase-1 mutations decrease protein stability and promote aggregation. The mutant monomer is thought to be an intermediate in the pathway from the superoxide dismutase-1 dimer to aggregate. Here we find that the monomeric copper-apo, zinc-holo protein is structurally perturbed and the apo-protein aggregates without reattainment of the monomer-dimer equilibrium. Intervention to stabilize the superoxide dismutase-1 dimer and inhibit aggregation is regarded as a potential therapeutic strategy. We describe protein-ligand interactions for two compounds, Isoproterenol and 5-fluorouridine, highlighted as superoxide dismutase-1 stabilizers. We find both compounds interact with superoxide dismutase-1 at a key region identified at the core of the superoxide dismutase-1 fibrillar aggregates, β-barrel loop II-strand 3, rather than the proposed dimer interface site. This illustrates the need for direct structural observations when developing compounds for protein-targeted therapeutics.

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Related in: MedlinePlus

Aggregation of monomeric and dimeric apo-A4V SOD1.Apo-A4V monomer and dimer size-exclusion chromatography elution profile obtained before and after 48 h incubation at 37 °C. Upper panel shows protein at 100 μM and lower panel shows 25 μM. In each case, a single elution is measured by absorption at 280 nm.
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f2: Aggregation of monomeric and dimeric apo-A4V SOD1.Apo-A4V monomer and dimer size-exclusion chromatography elution profile obtained before and after 48 h incubation at 37 °C. Upper panel shows protein at 100 μM and lower panel shows 25 μM. In each case, a single elution is measured by absorption at 280 nm.

Mentions: Dimeric and reduced apo monomeric A4V SOD1 have been shown to accumulate in an heterogeneous collection of high molecular weight soluble aggregates that increase in diameter as the incubation period increases141517. Figure 2 shows a comparison of the aggregation potential of monomeric and dimeric apo-A4V SOD1. Dimeric apo-A4V eluted from the SEC column at 13.1 ml. After 48 h, the dimer peak is almost completely absent and the majority of protein has moved to higher molecular weight species that elute with a peak at 12.6 ml. In contrast, monomeric A4V eluted at 13.7 ml and appears to aggregate more slowly. At concentrations that mimic the upper (100 μM) and lower (25 μM) bounds of intracellular SOD1 (ref. 29), 20 and 40% of the starting material remains as the monomer after 48 h. Aggregating protein accumulates in a species that elutes at 12.6 ml. It is interesting to note that in the metal apo form, both the monomer and dimer proceed to high molecular weight species, bypassing observable reattainment of the monomer–dimer equilibrium. This is the case at both high and low concentrations.


Ligand binding and aggregation of pathogenic SOD1.

Wright GS, Antonyuk SV, Kershaw NM, Strange RW, Samar Hasnain S - Nat Commun (2013)

Aggregation of monomeric and dimeric apo-A4V SOD1.Apo-A4V monomer and dimer size-exclusion chromatography elution profile obtained before and after 48 h incubation at 37 °C. Upper panel shows protein at 100 μM and lower panel shows 25 μM. In each case, a single elution is measured by absorption at 280 nm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3644087&req=5

f2: Aggregation of monomeric and dimeric apo-A4V SOD1.Apo-A4V monomer and dimer size-exclusion chromatography elution profile obtained before and after 48 h incubation at 37 °C. Upper panel shows protein at 100 μM and lower panel shows 25 μM. In each case, a single elution is measured by absorption at 280 nm.
Mentions: Dimeric and reduced apo monomeric A4V SOD1 have been shown to accumulate in an heterogeneous collection of high molecular weight soluble aggregates that increase in diameter as the incubation period increases141517. Figure 2 shows a comparison of the aggregation potential of monomeric and dimeric apo-A4V SOD1. Dimeric apo-A4V eluted from the SEC column at 13.1 ml. After 48 h, the dimer peak is almost completely absent and the majority of protein has moved to higher molecular weight species that elute with a peak at 12.6 ml. In contrast, monomeric A4V eluted at 13.7 ml and appears to aggregate more slowly. At concentrations that mimic the upper (100 μM) and lower (25 μM) bounds of intracellular SOD1 (ref. 29), 20 and 40% of the starting material remains as the monomer after 48 h. Aggregating protein accumulates in a species that elutes at 12.6 ml. It is interesting to note that in the metal apo form, both the monomer and dimer proceed to high molecular weight species, bypassing observable reattainment of the monomer–dimer equilibrium. This is the case at both high and low concentrations.

Bottom Line: Superoxide dismutase-1 mutations decrease protein stability and promote aggregation.We find both compounds interact with superoxide dismutase-1 at a key region identified at the core of the superoxide dismutase-1 fibrillar aggregates, β-barrel loop II-strand 3, rather than the proposed dimer interface site.This illustrates the need for direct structural observations when developing compounds for protein-targeted therapeutics.

View Article: PubMed Central - PubMed

Affiliation: Molecular Biophysics Group, Institute of Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Liverpool L69 7ZB, UK.

ABSTRACT
Mutations in the gene encoding Cu/Zn superoxide dismutase-1 cause amyotrophic lateral sclerosis. Superoxide dismutase-1 mutations decrease protein stability and promote aggregation. The mutant monomer is thought to be an intermediate in the pathway from the superoxide dismutase-1 dimer to aggregate. Here we find that the monomeric copper-apo, zinc-holo protein is structurally perturbed and the apo-protein aggregates without reattainment of the monomer-dimer equilibrium. Intervention to stabilize the superoxide dismutase-1 dimer and inhibit aggregation is regarded as a potential therapeutic strategy. We describe protein-ligand interactions for two compounds, Isoproterenol and 5-fluorouridine, highlighted as superoxide dismutase-1 stabilizers. We find both compounds interact with superoxide dismutase-1 at a key region identified at the core of the superoxide dismutase-1 fibrillar aggregates, β-barrel loop II-strand 3, rather than the proposed dimer interface site. This illustrates the need for direct structural observations when developing compounds for protein-targeted therapeutics.

Show MeSH
Related in: MedlinePlus