Linked Life Data

9158722

Source:http://linkedlifedata.com/resource/pubmed/id/9158722

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1997-6-19
pubmed:abstractText
The D-glutamic acid-adding enzyme of Escherichia coli, or MurD, was purified from an overproducing strain and a few aspects of its reaction mechanism were studied. The existence of a reactive cysteinyl residue was shown by the following experiments: (1) two thiol-modifying reagents, (5,5'-dithiobis)2-nitrobenzoic acid and 2-nitro-5-thiocyanobenzoic acid, inactivated the enzyme; (2) incubation with tetranitromethane led to inactivation and to the appearance of cysteic acid (not to 3-nitrotyrosine); (3) in each case, ATP or UDP-MurNAc-L-Ala (but not D-glutamic acid) protected the enzyme from inactivation. The existence of a reactive lysyl residue was shown by the action of 2,4,6-trinitrobenzenesulfonic acid, a reagent specific for lysyl residues present in phosphate-binding sites. The formation of an acyl phosphate intermediate was consistent with three types of results: (1) the molecular isotope exchange reaction, which took place only in the presence of phosphate, but which was not strictly dependent on the presence of ADP; (2) a release of phosphate, measured by the molybdate assay, observed when the enzyme was incubated with ATP and UDP-MurNAc-L-Ala (without D-glutamic acid); (3) the appearance of a new radioactive compound (besides ATP and Pi) after incubation for a few minutes with UDP-MurNAc-L-Ala and [gamma-32P]ATP. Finally, the fact that phosphinate 1 was a good inhibitor of the enzyme (IC50 = 0.7 microM) strongly suggested that a tetrahedral transition state follows the acyl phosphate in the reaction pathway.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
1076-6294
pubmed:author
pubmed:issnType
Print
pubmed:volume
2
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
51-4
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Study of the reaction mechanism of the D-glutamic acid-adding enzyme from Escherichia coli.
pubmed:affiliation
URA 1131 du CNRS, Båtiment 432, Université de Paris-Sud, Orsay, France.
pubmed:publicationType
Journal Article