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Molecular Properties of a Cholinergic Differentiation Factor from Muscle‐Conditioned Medium
Author(s) -
Weber Michel J.,
Raynaud Brigitte,
Delteil Christine
Publication year - 1985
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1985.tb07225.x
Subject(s) - choline acetyltransferase , stokes radius , chemistry , cholinergic , chromatography , spinal cord , elution , biophysics , medicine , endocrinology , biochemistry , sedimentation coefficient , biology , neuroscience , enzyme
Conditioned medium by a variety of rat nonneuronal cells contains a protein involved in the differentiation of cholinergic neurons in cultures prepared from newborn rat superior cervical ganglion, from nodose ganglion, and from embryonic spinal cord. We have determined some hydrodynamic properties of this factor using as a bioassay the increase in choline acetyltransferase activity in sympathetic neurons grown for 12–15 days in the presence of the factor. The Stokes' radius, measured by molecular sieving chromatography on an Ultrogel AcA 44 column, was similar to that of ovalbumin (27.6 Å). By analysis on 5–20% linear sucrose gradients made in H 2 O and D 2 O, we determined the partial specific volume (0.68 ml × g −1 ) and the sedimentation coefficient (2.1S). These data allowed the calculation of the molecular weight (21,000) and the frictional ratio f/f 0 (1.56). The elution pattern of the factor from a SynChropak CM 300 HPLC cation exchange column suggested that it was a basic protein. The activity of this factor was unaffected by heat treatment at 100°C for 10 min.