Simple and defined method to detect the SOD-1 mutants from patients with familial amyotrophic lateral sclerosis by mass spectrometry.
Mutations in Cu/Zn superoxide dismutase (SOD1) cause a subset of cases of familial amyotrophic lateral sclerosis (FALS). We established a simple and defined method to detect the mutant SODI in erythrocytes by electrospray ionization mass spectrometry (ESIMS) using materials precipitated with specific antiserum. Hemolysate was mixed with anti-SOD1 antiserum and the generated precipitate, which was soluble in the solvent for MS analysis, was injected on to an LC column connected to an ESI-mass spectrometer. MS spectra of the reduced SOD1 prepared from normal individuals showed ion peaks corresponding to free monomer SOD1. The spectra from FALS patients revealed doublet ion peaks corresponding to normal and mutant components. The ratios of mutant to normal SOD1 were about 1/2 in cases of (G37R) and (A4S), and about 0.15 in a case of (H46R). This method provides for the rapid diagnosis using small amount of specimens, and will contribute to elucidate the pathomechanism of FALS through the quantification of SOD1 mutants in erythrocytes and in tissues of nervous systems.
Department of Clinical Pathology, Osaka Medical College, Takatsuki, Japan.
T
T
Nakanishi
M
M
Kishikawa
A
A
Miyazaki
A
A
Shimizu
Y
Y
Ogawa
S
S
Sakoda
T
T
Ohi
H
H
Shoji
D019943:Amino Acid Substitution / Q000235:genetics; D000690:Amyotrophic Lateral Sclerosis / Q000097:blood / Q000209:etiology / Q000235:genetics*; D004247:DNA / Q000097:blood; D004252:DNA Mutational Analysis; D004912:Erythrocytes / Q000737:chemistry; D005820:Genetic Testing / Q000379:methods; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods; D009154:Mutation; D011233:Precipitin Tests; D013482:Superoxide Dismutase / Q000032:analysis* / Q000235:genetics*
D004247:DNA; D013482:Superoxide Dismutase