Decreased metallation and activity in subsets of mutant superoxide dismutases associated with familial amyotrophic lateral sclerosis
Authors
Hayward, Lawrence J.Rodriguez, Jorge A.
Kim, Ji W.
Tiwari, Ashutosh
Goto, Joy J.
Cabelli, Diane E.
Valentine, Joan Selverstone
Brown, Robert H. Jr.
UMass Chan Affiliations
Department of NeurologyDocument Type
Journal ArticlePublication Date
2002-02-21Keywords
Amino Acid SubstitutionAnimals
Binding Sites
Cell Line
Cloning, Molecular
Copper
DNA Primers
Humans
Insects
Motor Neuron Disease
Mutagenesis, Site-Directed
*Mutation
Protein Engineering
Protein Structure, Secondary
Recombinant Proteins
Spectrometry, Mass, Electrospray Ionization
Superoxide Dismutase
Variation (Genetics)
Life Sciences
Medicine and Health Sciences
Metadata
Show full item recordAbstract
Over 90 different mutations in the gene encoding copper/zinc superoxide dismutase (SOD1) cause approximately 2% of amyotrophic lateral sclerosis (ALS) cases by an unknown mechanism. We engineered 14 different human ALS-related SOD1 mutants and obtained high yields of biologically metallated proteins from an Sf21 insect cell expression system. Both the wild type and mutant "as isolated" SOD1 variants were deficient in copper and were heterogeneous by native gel electrophoresis. By contrast, although three mutant SOD1s with substitutions near the metal binding sites (H46R, G85R, and D124V) were severely deficient in both copper and zinc ions, zinc deficiency was not a consistent feature shared by the as isolated mutants. Eight mutants (A4V, L38V, G41S, G72S, D76Y, D90A, G93A, and E133 Delta) exhibited normal SOD activity over pH 5.5-10.5, per equivalent of copper, consistent with the presumption that bound copper was in the proper metal-binding site and was fully active. The H48Q variant contained a high copper content yet was 100-fold less active than the wild type enzyme and exhibited a blue shift in the visible absorbance peak of bound Cu(II), indicating rearrangement of the Cu(II) coordination geometry. Further characterization of these as-isolated SOD1 proteins may provide new insights regarding mutant SOD1 enzyme toxicity in ALS.Source
J Biol Chem. 2002 May 3;277(18):15923-31. Epub 2002 Feb 19. Link to article on publisher's siteDOI
10.1074/jbc.M112087200Permanent Link to this Item
http://hdl.handle.net/20.500.14038/42374PubMed ID
11854284Related Resources
Link to Article in PubMedae974a485f413a2113503eed53cd6c53
10.1074/jbc.M112087200