Linked Life Data

12773145

Source:http://linkedlifedata.com/resource/pubmed/id/12773145

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
Pt 3
pubmed:dateCreated
2003-5-29
pubmed:abstractText
Galactose oxidase (GO; EC 1.1.3.9) is a monomeric 68 kDa enzyme that contains a single copper and an amino acid-derived cofactor. The mechanism of this radical enzyme has been widely studied by structural, spectroscopic, kinetic and mutational approaches and there is a reasonable understanding of the catalytic mechanism and activation by oxidation to generate the radical cofactor that resides on Tyr-272, one of the copper ligands. Biogenesis of this cofactor involves the post-translational, autocatalytic formation of a thioether cross-link between the active-site residues Cys-228 and Tyr-272. This process is closely linked to a peptide bond cleavage event that releases the N-terminal 17-amino-acid pro-peptide. We have shown using pro-enzyme purified in copper-free conditions that mature oxidized GO can be formed by an autocatalytic process upon addition of copper and oxygen. Structural comparison of pro-GO (GO with the prosequence present) with mature GO reveals overall structural similarity, but with some regions showing significant local differences in main chain position and some active-site-residue side chains differing significantly from their mature enzyme positions. These structural effects of the pro-peptide suggest that it may act as an intramolecular chaperone to provide an open active-site structure conducive to copper binding and chemistry associated with cofactor formation. Various models can be proposed to account for the formation of the thioether bond and oxidation to the radical state; however, the mechanism of prosequence cleavage remains unclear.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0300-5127
pubmed:author
pubmed:issnType
Print
pubmed:volume
31
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
506-9
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Cofactor processing in galactose oxidase.
pubmed:affiliation
Astbury Centre for Structural Molecular Biology, School of Biochemistry and Molecular Biology, University of Leeds, Leeds LS2 9JT, UK.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Review, Research Support, Non-U.S. Gov't