Linked Life Data

1978721

Source:http://linkedlifedata.com/resource/pubmed/id/1978721

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
33
pubmed:dateCreated
1990-12-28
pubmed:abstractText
Treatment of pure 2-keto-4-hydroxyglutarate aldolase from Escherichia coli, a "lysine-type," Schiff-base mechanism enzyme, with the substrate analog bromopyruvate results in a time- and concentration-dependent loss of enzymatic activity. Whereas the substrates pyruvate and 2-keto-4-hydroxyglutarate provide greater than 90% protection against inactivation by bromopyruvate, no protective effect is seen with glycolaldehyde, an analog of glyoxylate. Inactivation studies with [14C] bromopyruvate show the incorporation of 1.1 mol of 14C-labeled compound/enzyme subunit; isolation of a radioactive peptide and determination of its amino acid sequence indicate that the radioactivity is associated with glutamate 45. Incubation of the enzyme with excess [14C]bromopyruvate followed by denaturation with guanidine.HCl allow for the incorporation of carbon-14 at cysteines 159 and 180 as well. Whereas the presence of pyruvate protects Glu-45 from being esterified, it does not prevent the alkylation of these 2 cysteine residues. The results indicate that Glu-45 of E. coli 2-keto-4-hydroxyglutarate aldolase is essential for catalytic activity, most likely acting as the amphoteric proton donor/acceptor that is required as a participant in the overall mechanism of the reaction catalyzed.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
265
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
20384-9
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Active-site residues of 2-keto-4-hydroxyglutarate aldolase from Escherichia coli. Bromopyruvate inactivation and labeling of glutamate 45.
pubmed:affiliation
Department of Biological Chemistry, University of Michigan, Ann Arbor 48109.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't