Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
1986-7-1
pubmed:abstractText
Evidence for a voltage-dependent regulatory (inhibitory) site on the nicotinic acetylcholine receptor to which acetylcholine binds was obtained in membrane vesicles prepared from the Torpedo californica electric organ. Two rate coefficients, JA and alpha, which pertain to the receptor-controlled ion flux, were measured. A 1000-fold concentration range of acetylcholine was used in a transmembrane voltage (Vm) range from 0 to -48 mV under a voltage-clamped condition at pH 7.4, 1 degrees C. The following observations were made. (i) At low acetylcholine concentrations, the value of JA, the rate coefficient for ion translocation by the active (nondesensitized) state of the receptor, increased with increasing concentration. (ii) JA decreased at high acetylcholine concentrations. (iii) In contrast, alpha, the rate coefficient for receptor desensitization, did not show such a decrease. (iv) When the transmembrane potential of the vesicle membrane was changed to more negative values, the value of KR (the dissociation constant for binding of acetylcholine to the regulatory site) decreased by a factor of approximately 9 for a 25 mV change in Vm, while KI (the dissociation constant for binding of acetylcholine to the receptor site that controls channel opening) did not show such a change and has a value of 80 microM. When Vm is -48 mV, KR has a value of 8 microM. (v) The effect of a transmembrane voltage on the regulatory site was reversible and occurred within the time resolution (5 ms) of the quench-flow technique used in the measurements.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
8
pubmed:volume
25
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1770-6
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1986
pubmed:articleTitle
Acetylcholine receptor: characterization of the voltage-dependent regulatory (inhibitory) site for acetylcholine in membrane vesicles from Torpedo californica electroplax.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.