Linked Life Data

10446378

Source:http://linkedlifedata.com/resource/pubmed/id/10446378

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
1999-10-1
pubmed:abstractText
Human butyrylcholinesterase displays substrate activation with positively charged butyrylthiocholine (BTC) as the substrate. Peripheral anionic site (PAS) residues D70 and Y332 appear to be involved in the initial binding of charged substrates and in activation control. To determine the contribution of PAS residues to binding and hydrolysis of quaternary substrates and activation control, the single mutants D70G/Y and Y332F/A/D and the double mutants Y332A/D70G and Y332D/D70Y were studied. Steady-state hydrolysis of the charged substrates, BTC and succinyldithiocholine, and the neutral ester o-nitrophenyl butyrate was measured. In addition, inhibition of wild-type and mutant enzymes by tetramethylammonium was investigated, at low concentrations of BTC. Single and double mutants of D70 and Y332 showed little or no substrate activation, suggesting that both residues were important for activation control. The effects of double mutations on D70 and Y332 were complex. Double-mutant cycle analysis provided evidence for interaction between these residues. The category of interaction (either synergistic, additive, partially additive or antagonistic) was found to depend on the nature of the substrate and on measured binding or kinetic parameters. This complexity reflects both the cross-talk between residues involved in the sequential formation of productive Michaelian complexes and the effect of peripheral site residues on catalysis. It is concluded that double mutations on the PAS induce a conformational change in the active site gorge of butyrylcholinesterase that can alter both substrate binding and enzyme acylation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
17
pubmed:volume
1433
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
281-93
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Interaction between the peripheral site residues of human butyrylcholinesterase, D70 and Y332, in binding and hydrolysis of substrates.
pubmed:affiliation
Centre de Recherches du Service de Santé des Armées, Unité d'Enzymologie, P.O. Box 87, 38702, La Tronche Cedex, France. 100335.404@compuserve.com
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't