Linked Life Data

10052943

Source:http://linkedlifedata.com/resource/pubmed/id/10052943

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
1999-3-22
pubmed:abstractText
An unusual flavoprotein disulfide reductase, which catalyzes the NADPH-dependent reduction of CoASSCoA, has recently been purified from the human pathogen Staphylococcus aureus [delCardayré, S. B., Stock, K. P., Newton, G. L., Fahey, R. C., and Davies, J. E. (1998) J. Biol. Chem. 273, 5744-5751]. Coenzyme A-disulfide reductase (CoADR) lacks the redox-active protein disulfide characteristic of the disulfide reductases; instead, NADPH reduction yields 1 protein-SH and 1 CoASH. Furthermore, the CoADR sequence reveals the presence of a single putative active-site Cys (Cys43) within an SFXXC motif also seen in the Enterococcus faecalis NADH oxidase and NADH peroxidase, which use a single redox-active cysteine-sulfenic acid in catalysis. In this report, we provide a detailed examination of the equilibrium properties of both wild-type and C43S CoADRs, focusing on the role of Cys43 in the catalytic redox cycle, the behavior of both enzyme forms on reduction with dithionite and NADPH, and the interaction of NADP+ with the corresponding reduced enzyme species. The results of these analyses, combined with electrospray mass spectrometric data for the two oxidized enzyme forms, fully support the catalytic redox role proposed for Cys43 and confirm that this is the attachment site for bound CoASH. In addition, we provide evidence indicating dramatic thermodynamic inequivalence between the two active sites per dimer, similar to that documented for the related enzymes mercuric reductase and NADH oxidase; only 1 FAD is reduced with NADPH in wild-type CoADR. The EH2.NADPH/EH4.NADP+ complex which results is reoxidized quantitatively in titrations with CoASSCoA, supporting a possible role for the asymmetric reduced dimer in catalysis.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Coenzyme A, http://linkedlifedata.com/resource/pubmed/chemical/Cysteine, http://linkedlifedata.com/resource/pubmed/chemical/Dithionite, http://linkedlifedata.com/resource/pubmed/chemical/Ferricyanides, http://linkedlifedata.com/resource/pubmed/chemical/Isoenzymes, http://linkedlifedata.com/resource/pubmed/chemical/NADH, NADPH Oxidoreductases, http://linkedlifedata.com/resource/pubmed/chemical/NADP, http://linkedlifedata.com/resource/pubmed/chemical/Recombinant Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Serine, http://linkedlifedata.com/resource/pubmed/chemical/coenzyme A disulfide, http://linkedlifedata.com/resource/pubmed/chemical/disulfide reductase (NADH), http://linkedlifedata.com/resource/pubmed/chemical/hexacyanoferrate III
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
2
pubmed:volume
38
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2725-37
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Coenzyme A-disulfide reductase from Staphylococcus aureus: evidence for asymmetric behavior on interaction with pyridine nucleotides.
pubmed:affiliation
Department of Biochemistry, Wake Forest University Medical Center, Winston-Salem, North Carolina 27157, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.