Linked Life Data

10082962

Source:http://linkedlifedata.com/resource/pubmed/id/10082962

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1999-5-6
pubmed:abstractText
Fasciculin, a peptidic toxin from snake venom, inhibits mammalian and fish acetylcholinesterases (AChE) by binding to the peripheral site of the enzyme. This site is located at the rim of a narrow, deep gorge which leads to the active center triad, located at its base. The proposed mechanisms for AChE inhibition by fasciculin include allosteric events resulting in altered conformation of the AChE active center gorge. However, a fasciculin-induced altered topography of the active center gorge has not been directly demonstrated. Using electron paramagnetic resonance with the spin-labeled organophosphate 1-oxyl-2,2,6, 6-tetramethyl-4-piperidinylethylphosphorofluoridate (EtOSL) specifically bound to the catalytic serine of mouse AChE (mAChE), we show that bound fasciculin on mAChE slows down, but does not prevent phosphorylation of the active site serine by EtOSL and protects the gorge conformation against thermal denaturation. Most importantly, a restricted freedom of motion of the spin label bound to the fasciculin-associated mAChE, compared to mAChE, is evidenced. Molecular models of mAChE and fasciculin-associated mAChE with tethered EtOSL enantiomers indicate that this restricted motion is due to greater proximity of the S-EtOSL nitroxide radical to the W86 residue in the fasciculin-associated enzyme. Our results demonstrate a topographical alteration indicative of a restricted conformation of the active center gorge of mAChE with bound fasciculin at its rim.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
19
pubmed:volume
1430
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
349-58
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Electron paramagnetic resonance reveals altered topography of the active center gorge of acetylcholinesterase after binding of fasciculin to the peripheral site.
pubmed:affiliation
Jozef Stefan Institute, Ljubljana, Slovenia.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't