Linked Life Data

20333421

Source:http://linkedlifedata.com/resource/pubmed/id/20333421

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2010-5-27
pubmed:abstractText
Nickel superoxide dismutase (NiSOD) is unique among the family of superoxide dismutase enzymes in that it coordinates Cys residues (Cys2 and Cys6) to the redox-active metal center and exhibits a hexameric quaternary structure. To assess the role of the Cys residues with respect to the activity of NiSOD, mutations of Cys2 and Cys6 to Ser (C2S-NiSOD, C6S-NiSOD, and C2S/C6S-NiSOD) were carried out. The resulting mutants do not catalyze the disproportionation of superoxide, but retain the hexameric structure found for wild-type NiSOD and bind Ni(II) ions in a 1:1 stoichiometry. X-ray absorption spectroscopic studies of the Cys mutants revealed that the nickel active-site structure for each mutant resembles that of C2S/C6S-NiSOD and demonstrate that mutation of either Cys2 or Cys6 inhibits coordination of the remaining Cys residue. Mutation of one or both Cys residue(s) in NiSOD induces the conversion of the low-spin Ni(II) site in the native enzyme to a high-spin Ni(II) center in the mutants. This result indicates that coordination of both Cys residues is required to generate the native low-spin configurations and maintain catalytic activity. Analysis of the quaternary structure of the Cys mutants by differential scanning calorimetry, mass spectrometry, and size-exclusion chromatography revealed that the Cys ligands, particularly Cys2, are also important for stabilizing the hexameric quaternary structure of the native enzyme.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
1432-1327
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
15
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
795-807
pubmed:dateRevised
2011-9-26
pubmed:meshHeading
pubmed:year
2010
pubmed:articleTitle
Nickel superoxide dismutase: structural and functional roles of Cys2 and Cys6.
pubmed:affiliation
Department of Chemistry, University of Massachusetts at Amherst, MA 01003, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, N.I.H., Extramural