44 research outputs found
The Trouble with Chill Pills AndreaToneThe Age of Anxiety2008Basic Books320 pp., $26.95 hardcover
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Purification of Acetylcholine-Receptor Enriched Membranes by Use of Affinity Partitioning
Membrane fragments rich in acetylcholine receptor from the
electric organ of Torpedo caLifornica were purified by a combination
of classical methods and affinity partitioning, a method analogous
to affinity chromatography. Affinity partitioning is based upon the
phase partition method where two water-rich liquid phases are
formed upon the addition of sufficient quantities of water soluble
polymers such as poly(ethylene oxide) and dextran. A phase
system in which less than 2°/o of acetylcholinesterase, adenosine
triphosphatase and a-toxin binding activities di,s,tribute ilnto the
poly(ethylene oxide) rich phase was chosen. By adding cholinergic
derivatives of poly(ethylene oxide), selective changes in the
distribution of membrane fragments rich in acetylcholine receptor
into the poly(ethylene oxide) rich were achieved. Sodium dodecyl
sulfate polyacrylamide gel electrophoresis as well as assay of
cobra a-toxin binding, acetylcholinesterase and adenosinetriphosphatase activities indicate that substantial purification of membrane- bound acetylcholine receptor was achieved
MICROTUBULE PROTEIN : Identification in and Transport to Nerve Endings
The subunit protein of microtubules, tubulin, has been demonstrated to be present in isolated nerve endings by gel electrophoresis, amino acid composition, and peptide mapping. The tubulin constitutes approximately 28% of the soluble protein of the nerve endings. The transport of tubulin to the nerve endings has been demonstrated and its relationship to slow transport is discussed
Purification of Acetylcholine-Receptor Enriched Membranes by Use of Affinity Partitioning
Membrane fragments rich in acetylcholine receptor from the
electric organ of Torpedo caLifornica were purified by a combination
of classical methods and affinity partitioning, a method analogous
to affinity chromatography. Affinity partitioning is based upon the
phase partition method where two water-rich liquid phases are
formed upon the addition of sufficient quantities of water soluble
polymers such as poly(ethylene oxide) and dextran. A phase
system in which less than 2°/o of acetylcholinesterase, adenosine
triphosphatase and a-toxin binding activities di,s,tribute ilnto the
poly(ethylene oxide) rich phase was chosen. By adding cholinergic
derivatives of poly(ethylene oxide), selective changes in the
distribution of membrane fragments rich in acetylcholine receptor
into the poly(ethylene oxide) rich were achieved. Sodium dodecyl
sulfate polyacrylamide gel electrophoresis as well as assay of
cobra a-toxin binding, acetylcholinesterase and adenosinetriphosphatase activities indicate that substantial purification of membrane- bound acetylcholine receptor was achieved