Linked Life Data

2902091

Source:http://linkedlifedata.com/resource/pubmed/id/2902091

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
30
pubmed:dateCreated
1988-11-21
pubmed:abstractText
The dependence of glutamate uptake on ATP-generated proton electrochemical potential was studied in a highly purified preparation of synaptic vesicles from rat brain. At low chloride concentration (4 mM), the proton pump present in synaptic vesicles generated a large membrane potential (inside-positive), associated with only minor acidification. Under these conditions, the rate of L-[3H]glutamate uptake was maximal. In addition, L-glutamate induced acidification of the vesicle interior. D-Glutamate produced only 40% of the effect, and L-aspartate or gamma-aminobutyric acid produced less than 5%. The initial rate of glutamate-induced acidification increased with increasing glutamate concentration. It was saturable and showed first-order kinetics (KM = 0.32 mM). Correspondingly, L-glutamate induced a small reduction in the membrane potential. The rate of ATP hydrolysis was unaffected. In comparison, glutamate had no effect on acidification or membrane potential in resealed membranes of chromaffin granules. At high chloride concentration (150 mM), the vesicular proton pump generated a large pH difference, associated with a small change in membrane potential. Under these conditions, uptake of L-[3H]glutamate by synaptic vesicles was low. For reconstitution, vesicle proteins were solubilized with the detergent sodium cholate, supplemented with brain phospholipids, and incorporated into liposomes. Proton pump and glutamate uptake activities of the proteoliposomes showed properties similar to those of intact vesicles indicating that the carrier was reconstituted in a functionally active form. It is concluded that glutamate uptake by synaptic vesicles is dependent on the membrane potential and that all components required for uptake are integral parts of the vesicle membrane.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
263
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
15423-8
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Glutamate uptake by brain synaptic vesicles. Energy dependence of transport and functional reconstitution in proteoliposomes.
pubmed:affiliation
Department of Neurochemistry, Max-Planck-Institute for Psychiatry, Martinsried, Federal Republic of Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't