Linked Life Data

9183003

Source:http://linkedlifedata.com/resource/pubmed/id/9183003

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1997-7-1
pubmed:abstractText
The inhibition mechanism of the dimeric human placenta glutathione transferase (GST) P1-1 by calvatic acid and the reaction intermediates, i.e. the diazocyanide analogue of calvatic acid, has been investigated at pH 7.0 and 30.0 degrees C. Experiments performed at different molar ratios of inhibitor/GST P1-1 indicate that 1 mol calvatic acid inactivates 1 mol GST P1-1, containing two catalytically equivalent active sites. However, 2 mol of the diazocyanide analogue of calvatic acid inactivate 1 mol GST P1-1. Two disulfide bridges/dimer, probably between Cys47 and Cys101, have been formed during the reaction of GST P1-1 with calvatic acid and its diazocyanide analogue. The apparent second-order rate constants for GST P1-1 inactivation by calvatic acid and its diazocyanide analogue are 2.4+/-0.3 M(-1) s(-1) and (8.5+/-0.7) x 10(3) M(-1) s(-1), respectively. The reaction of calvatic acid with free L-cysteine can be described by a simple process with an apparent second-order rate constant of (5.0+/-0.4) x 10(1) M(-1) s(-1). In contrast, a transient species occurs during the reaction of the diazocyanide analogue of calvatic acid with free L-cysteine. Kinetics may be described by a second-order process [the rate constant being (8.0+/-0.5) x 10(3) M(-1) s(-1)] followed by a first-order decay [the rate constant corresponding to (1.2+/-0.1) x 10(1) s(-1)]. Calvatic acid represents an enzyme inhibitor acting much slower than its reaction intermediates (i.e. its diazocyanide analogue).
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0014-2956
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
245
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
663-7
pubmed:dateRevised
2007-7-23
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Inhibition of human placenta glutathione transferase P1-1 by the antibiotic calvatic acid and its diazocyanide analogue--evidence for multiple catalytic intermediates.
pubmed:affiliation
Dipartimento di Biologia di Base ed Applicata, Università di L'Aquila,Italy.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't