Linked Life Data

9751137

Source:http://linkedlifedata.com/resource/pubmed/id/9751137

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1998-10-22
pubmed:abstractText
Choline acetyltransferase (ChAT), the enzyme which catalyses the biosynthesis of the neurotransmitter acetylcholine, exists in a soluble and membrane-bound form in cholinergic nerve terminals of different animal species. This study was performed on the enzyme present in Drosophila central nervous system. We show that the two forms of the enzyme have the same apparent molecular weight (75 kDa) when analysed by immunoblotting using an antibody we raised against the recombinant enzyme. According to different authors, membrane-bound enzyme might be associated with synaptic vesicles or plasma membrane. Subfractionation of Drosophila head homogenates in linear glycerol gradients showed that ChAT does not associate with synaptic vesicles. Analysis of ChAT activity and immunoreactivity showed that two peaks of ChAT were produced. One peak was present in fractions containing soluble components and the other was associated with rapidly sedimenting membranes containing plasma membranes. ChAT in the first peak was mainly hydrophilic. A large proportion of ChAT associated with rapidly sedimenting membranes was amphiphilic. Further fractionation of these membranes by flotation in sucrose gradients showed that membrane-associated ChAT sedimented in fractions containing plasma membrane marker. Membrane-bound ChAT was neither solubilized nor converted to hydrophilic enzyme after membrane treatment with 1 M hydroxylamine, suggesting that the enzyme is not palmitoylated and therefore not anchored to membrane through thioester-linked long chain fatty acid. Partial solubilization of ChAT present on membranes with urea and carbonate suggests that this form of ChAT is a peripheral membrane protein. Carbonate solubilization of membrane-bound ChAT converted the enzyme from hydrophobic to hydrophilic protein.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0953-816X
pubmed:author
pubmed:issnType
Print
pubmed:volume
10
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1644-53
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Study of subcellular localization of membrane-bound choline acetyltransferase in Drosophila central nervous system and its association with membranes.
pubmed:affiliation
Department of Pharmacology and APSIC, Centre Médical Universitaire, Geneva, Switzerland.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't