A common property of amyotrophic lateral sclerosis-associated variants: destabilization of the copper/zinc superoxide dismutase electrostatic loop.
At least 119 mutations in the gene encoding copper/zinc superoxide dismutase (SOD1) cause amyotrophic lateral sclerosis by an unidentified toxic gain of function. We compared the dynamic properties of 13 as-isolated, partially metallated, SOD1 variant enzymes using hydrogen-deuterium exchange. We identified a shared property of these familial amyotrophic lateral sclerosis-related SOD1 variants, namely structural and dynamic change affecting the electrostatic loop (loop VII) of SOD1. Furthermore, SOD1 variants that have severely compromised metal binding affinities demonstrated additional structural and dynamic changes to the zinc-binding loop (loop IV) of SOD1. Although the biological consequences of increased loop VII mobility are not fully understood, this common property is consistent with the hypotheses that SOD1 mutations exert toxicity via aggregation or aberrant association with other cellular constituents.
Molnar
Kathleen S
KS
Department of Chemistry, Volen Center, Brandeis University, Waltham, Massachusetts 02454, USA.
Karabacak
N Murat
NM
Johnson
Joshua L
JL
Wang
Qi
Q
Tiwari
Ashutosh
A
Hayward
Lawrence J
LJ
Coales
Stephen J
SJ
Hamuro
Yoshitomo
Y
Agar
Jeffrey N
JN
D000690:Amyotrophic Lateral Sclerosis / Q000201:enzymology* / Q000235:genetics; D001665:Binding Sites; D014644:Genetic Variation; D006801:Humans; D008958:Models, Molecular; D009154:Mutation; D011485:Protein Binding; D011487:Protein Conformation; D055672:Static Electricity; D013482:Superoxide Dismutase / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D000072105:Superoxide Dismutase-1
C000606290:SOD1 protein, human; D013482:Superoxide Dismutase; D000072105:Superoxide Dismutase-1