Immunological detection of mediatophore in motor end-plates and electric organ subcellular fractions of torpedo marmorata.
A rabbit antiserum to mediatophore, a nerve terminal membrane protein involved in calcium dependent ACh release, was raised after immunization with the purified protein. An immunological assay for mediatophore was then developed and the subcellular distribution of this protein in Torpedo electric organ fractions was studied. A good agreement was obtained between the distribution in the different fractions of the antigen and of mediatophore related acetylcholine releasing activity as determined by reconstitution in proteoliposomes. Mediatophore was highly concentrated in presynaptic plasma membranes of electric organ, while very low contents were observed in electric nerves and electric lobes. Although some mediatophore was found in synaptic vesicle fractions, this most probably resulted from presynaptic membrane contamination as evaluated with other presynaptic membrane markers. Nerve terminals of motor end-plates were strongly stained with anti-mediatophore antibodies.
Morel
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N
Département de Neurochimie, Laboratoire de Neurobiologie Cellulaire et Moléculaire, C.N.R.S. 91198 Gif-sur-Yvette Cedex, France.
Manaranche
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R
Israël
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M