Coupling of native IEF and extended X-ray absorption fine structure to characterize zinc-binding sites from pI isoforms of SOD1 and A4V pathogenic mutant.
Electrophoresis
; 33(8): 1276-81, 2012 Apr.
Article
em En
| MEDLINE
| ID: mdl-22589106
ABSTRACT
Extended X-ray absorption fine structure (EXAFS) has already provided high-resolution structures of metal-binding sites in a wide variety of metalloproteins. Usually, EXAFS is performed on purified metalloproteins either in solution or crystallized form but purification steps are prone to modify the metallation state of the protein. We developed a protocol to couple EXAFS analysis to metalloprotein separation using native gel electrophoresis. This coupling opens a large field of applications as metalloproteins can be characterized in their native state avoiding purification steps. Using native isoelectric focusing, the method enables the EXAFS analysis of metalloprotein pI isoforms. We applied this methodology to SOD1, wild-type, and Ala4Val mutant (A4V), a mutation found in amyotrophic lateral sclerosis (ALS) because decreased Zn affinity to SOD1 mutants is suggested to be involved in the pathogenesis of this neurodegenerative disease. We observed similar coordination structures for Zn in wild-type and mutant proteins, in all measured pI isoforms, demonstrating the feasibility of EXAFS on electrophoresis gels and suggesting that the Zn-binding site is not structurally modified in A4V SOD1 mutant.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Superóxido Dismutase
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Zinco
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Espectroscopia por Absorção de Raios X
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Focalização Isoelétrica
Idioma:
En
Ano de publicação:
2012
Tipo de documento:
Article