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ACTIVATION, INHIBITION AND AGGREGATION OF CHOLINE ACETYLTRANSFERASE (EC 2.3.1.6)
Author(s) -
Chao L.P.,
Wolfgram F.
Publication year - 1974
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.1471-4159.1974.tb04393.x
Subject(s) - chemistry , hydrochloride , guanidine , chromatography , sodium , silver acetate , cadmium chloride , choline acetyltransferase , ammonium chloride , potassium , size exclusion chromatography , choline , chloride , enzyme , nuclear chemistry , biochemistry , cadmium , organic chemistry , acetylcholine , biology , pharmacology
—Mercuric chloride, silver acetate and cupric sulphate (0·1 m m ) completely inhibited purified choline acetyltransferase from bovine caudate nuclei. At the same concentration cadmium chloride and zinc acetate gave a 50 per cent inhibition. Potassium and sodium salts more than doubled the enzymatic activity while creatinine hydrochloride more than tripled it. Guanidine hydrochloride was less effective than creatinine hydrochloride but more effective than KCl and NaCl. Sodium chloride and creatinine hydrochloride had a synergistic effect on the enzyme. When ammonium sulphate was used to fractionate the choline acetyltransferase that had been extracted from bovine caudate nuclei, the enzyme aggregated into different molecular sizes as determined by exclusion chromatography on Bio‐gel A‐1·5 m. The molecular weight of the largest aggregate was at least 10 6 daltons. The initial tissue extract contained only one molecular species of ChAc as did a partially purified preparation in which ammonium sulphate was not used in the purification.