An immunological epitope selective for pathological monomer-misfolded SOD1 in ALS.
Misfolding of Cu/Zn-superoxide dismutase (SOD1) is emerging as a mechanism underlying motor neuron degeneration in individuals with amyotrophic lateral sclerosis (ALS) who carry a mutant SOD1 gene (SOD1 ALS). Here we describe a structure-guided approach to developing an antibody that specifically recognizes monomer-misfolded forms of SOD1. We raised this antibody to an epitope that is normally buried in the SOD1 native homodimer interface. The SOD1 exposed dimer interface (SEDI) antibody recognizes only those SOD1 conformations in which the native dimer is disrupted or misfolded and thereby exposes the hydrophobic dimer interface. Using the SEDI antibody, we established the presence of monomer-misfolded SOD1 in three ALS mouse models, with G37R, G85R and G93A SOD1 mutations, and in a human individual with an A4V SOD1 mutation. Despite ubiquitous expression, misfolded SOD1 was found primarily within degenerating motor neurons. Misfolded SOD1 appeared before the onset of symptoms and decreased at the end stage of the disease, concomitant with motor neuron loss.
Rakhit
Rishi
R
Department of Biochemistry, University of Toronto and Ontario Cancer Institute, 101 College Street, Toronto, Ontario M5G 1L7, Canada.
Robertson
Janice
J
Vande Velde
Christine
C
Horne
Patrick
P
Ruth
Deborah M
DM
Griffin
Jennifer
J
Cleveland
Don W
DW
Cashman
Neil R
NR
Chakrabartty
Avijit
A
D000595:Amino Acid Sequence; D000690:Amyotrophic Lateral Sclerosis / Q000201:enzymology* / Q000276:immunology* / Q000473:pathology; D000818:Animals; D000906:Antibodies / Q000378:metabolism; D004195:Disease Models, Animal; D000939:Epitopes / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D051379:Mice; D008822:Mice, Transgenic; D008969:Molecular Sequence Data; D011487:Protein Conformation; D017510:Protein Folding; D011817:Rabbits; D051381:Rats; D013347:Subcellular Fractions / Q000378:metabolism; D013482:Superoxide Dismutase / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D000072105:Superoxide Dismutase-1
D000906:Antibodies; D000939:Epitopes; C000606290:SOD1 protein, human; C000606291:Sod1 protein, mouse; C000606292:Sod1 protein, rat; D013482:Superoxide Dismutase; D000072105:Superoxide Dismutase-1