Linked Life Data

3838098

Source:http://linkedlifedata.com/resource/pubmed/id/3838098

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1985-2-21
pubmed:abstractText
Ethylcholine mustard aziridinium ion (AF64A, MEChMAz) has been proposed as a cholinergic neuron-specific neurotoxin. We report that in further studies on its mechanism of action incubation of the cholinergic neuroblastoma X glioma cell line, NG-108-15, with 100 microM AF64A resulted in a rapid decrease in cellular choline acetyltransferase (ChAT) activity which preceded cytotoxicity. Thus, a 60-85% decrease in ChAT activity was measured within 5 h of AF64A exposure, whereas cell lysis (measured as the release of the cytosolic enzyme lactate dehydrogenase into the medium) did not become apparent until 18 h of AF64A exposure. This led us to examine the effects of AF64A on partially purified ChAT. We report a concentration- and time-dependent inhibition of partially purified ChAT by AF64A that could not be reversed by dialysis but could be prevented by coincubation of the enzyme and AF64A with choline but not with acetyl-coenzyme A. We present kinetic evidence that choline and AF64A compete for the same site on the enzyme. In addition, thiosulfate, which inactivates the aziridinium ion, eliminated AF64A's capacity to inhibit the enzyme. AF64A also irreversibly inhibited partially purified choline kinase and acetylcholinesterase but not lactate dehydrogenase, alcohol dehydrogenase, carboxypeptidase A, or chymotrypsinogen, enzymes that do not use choline as a substrate or product. Thus, the data suggest that AF64A acts as an irreversible active site directed inhibitor of ChAT and possibly other enzymes recognizing choline.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0022-3042
pubmed:author
pubmed:issnType
Print
pubmed:volume
44
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
439-45
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1985
pubmed:articleTitle
AF64A: an active site directed irreversible inhibitor of choline acetyltransferase.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't