Quantitation of cation transport by reconstituted membrane vesicles containing purified acetylcholine receptor.
- 1 February 1981
- journal article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences
- Vol. 78 (2) , 775-779
- https://doi.org/10.1073/pnas.78.2.775
Abstract
A stopped-flow spectroscopic technique was used to study the kinetics of ion transport by reconstituted membrane preparations containing purified acetylcholine receptor. Influx of thallium (I) into membrane vesicles was monitored as a decrease, due to quenching by the thallous ion, in the fluorescence of an entrapped fluorophore. In a reproducible manner, the reconstituted receptor responded to cholinergic agonists by mediating rapid ion transport in the millisecond time range. The effect of agonists was blocked by receptor desensitization and by histrionicotoxin and was absent in membrane vesicles lacking receptor. Analysis of the fast kinetics of cation transport produced by saturating concentrations of agonists yielded an estimated rate of transport through a single reconstituted receptor channel. Comparison of this rate with those reported for in vivo preparations and for purified membranes shows that the reconstituted protein closely resembles the physiologically active receptor.Keywords
This publication has 28 references indexed in Scilit:
- Reconstitution of the purified acetylcholine receptor from Torpedo californicaFEBS Letters, 1979
- Affinity-directed crosslinking of membrane-bound acetylcholine receptor polypeptides with photolabile .alpha.-bungarotoxin derivativesBiochemistry, 1979
- Reconstitution of a functional acetylcholine regulator under defined conditionsFEBS Letters, 1979
- Carbamylcholine-induced rapid cation efflux from reconstituted membrane vesicles containing purified acetylcholine receptorBiochemical and Biophysical Research Communications, 1979
- Rapid cation flux from Torpedo californica membrane vesicles: Comparison of acetylcholine receptor enriched and selectively extracted preparationsBiochemical and Biophysical Research Communications, 1979
- Bromoacetylcholine as an affinity label of the acetylcholine receptor from Torpedo californicaBiochemical and Biophysical Research Communications, 1978
- Selective photoaffinity labeling of acetylcholine receptor using a cholinergic analogBiochemistry, 1977
- Interactions of perhydrohistrionicotoxin with postsynaptic membranesBiochemical and Biophysical Research Communications, 1977
- Fractionation and partial characterization of membrane particles from Torpedo californica electroplaxBiochemistry, 1973
- Purification fromTorpedo marmorata electric tissue of membrane fragments particularly rich in cholinergic receptor proteinFEBS Letters, 1972