title: Purification of chicken brain choline acetyltransferase.
abstract: Chicken brain choline acetyltransferase was purified to homogeneity using ammonium sulfate fractionation, followed by chromatography on DEAE-Sephadex (A-25), hydroxyapatite, Sephadex G-150, immunoabsorption and Sepharose-CoA columns. A purification of 3500-fold was achieved and the final preparation had a specific activity of 2:32 ?mol acetylcholine formed per minute per milligram protein. The purified chicken choline acetyltransferase migrated as a single band on polyacrylamide gel electrophoresis in the presence and absence of sodium deodecyl sulfate. The native enzyme, with a molecular weight of 67,000 daltons, consists of two subunits of identical molecular weight. Chicken choline acetyltransferase has a sharp pH optimum of 7.4. It is activated by sodium chloride and potassium chloride but inhibited by cupric ion and N-ethylmaleimide.
authors.affiliation: Division of Neurological Sciences, Department of Psychiatry, University of British Columbia, Vancouver, B.C., Canada V6T 1W5.
authors.forename: J H
authors.initials: JH
authors.lastname: Peng
authors.forename: K
authors.initials: K
authors.lastname: Ma
authors.forename: S C
authors.initials: SC
authors.lastname: Sung