Linked Life Data

3114245

Source:http://linkedlifedata.com/resource/pubmed/id/3114245

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
24
pubmed:dateCreated
1987-9-30
pubmed:abstractText
Reconstitution of wild-type apoaspartate aminotransferase from Escherichia coli with [4'-3H]pyridoxamine 5'-phosphate results in stereospecific release of the pro-S C-4' 3H to the solvent. The reaction follows first-order kinetics (t1/2 = 15 min at pH 7.5 and 25 degrees C), its rate constant being similar to that found previously with mitochondrial aspartate aminotransferase from chicken (Tobler, H.P., Christen, P., and Gehring, H. (1986) J. Biol. Chem. 261, 7105-7108). Substituting the active site residue Lys258 by alanine via site-directed mutagenesis yields a catalytically inactive enzyme (Malcolm, B. A., and Kirsch, J. F. (1985) Biochem. Biophys. Res. Commun. 132, 915-921). This mutant enzyme fails to release any measurable 3H from bound [4'-3H]pyridoxamine 5'-phosphate. The data are consistent with earlier proposals that Lys258 is indispensable for the ketimine/aldimine tautomerization, and corroborate the previous conclusion that 3H exchange from enzyme-bound pyridoxamine 5'-phosphate mechanistically corresponds to the deprotonation at C-4' of the ketimine intermediate during the transamination reaction.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
262
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
11446-8
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1987
pubmed:articleTitle
The stereospecific labilization of the C-4' pro-S hydrogen of pyridoxamine 5'-phosphate is abolished in (Lys258----Ala) aspartate aminotransferase.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't