Linked Life Data

1318718

Source:http://linkedlifedata.com/resource/pubmed/id/1318718

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1992-7-23
pubmed:abstractText
Pyrroloquinoline quinone (PQQ) catalyzes the oxidation of cysteamine at neutral pH with a second order rate constant K2 = 0.45 M-1 s-1. The reduction of PQQ was monitored by absorption and fluorescence spectroscopy, whereas the oxidation of cysteamine to cystamine was followed by titration with 5,5'-dithiobis(2-nitrobenzoic acid). PQQ also catalyzes the oxidation of thiol groups critically connected with the function of two proteins, i.e. thioredoxin and phosphoribulose kinase. The reaction of PQQ with reduced thioredoxin brings about the oxidation of two thiol groups of the oxireductase, whereas the enzyme phosphoribulose kinase is inactivated at 25 degrees C. The oxidized disulfide bond of phosphoribulose kinase is reduced by dithiothreitol and the enzyme recovers catalytic activity. The ability of PQQ to catalyze the oxidation of vicinal cysteinyl residues to generate disulfide bonds under mild experimental conditions can be exploited to define the precise role of modified thiol residues in either catalysis or stabilization of protein structure.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0951-6433
pubmed:author
pubmed:issnType
Print
pubmed:volume
3
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
257-60
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Pyrroloquinoline quinone (coenzyme PQQ) and the oxidation of SH residues in proteins.
pubmed:affiliation
Department of Biochemistry, University of Tennessee, Knoxville 37916.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S.