CELL FREE "CHOLINE ACETYLASE" FROM LACTOBACILLUS PLANTARUM

Abstract

The conventional methods employed to extract "choline acetylase" from animal tissues have been found not to be applicable to the extraction of the bacterial enzyme. A method has been developed for the extraction of a highly active cell free "choline acetylase" from Lactobacillus plantarum. The procedure involves disruption of lyophilized cells with glass powder and resolution of lipoprotein complexes through extraction of the cell debris with n-butyl alcohol followed by acetone drying and aequeous extraction of the enzyme from the acetone dried cell residue. The enzyme extract acetylates choline when incubated under anaerobic conditions with the substrates choline and acetate and requires the presence of ATP and cysteine. Coenzyme A markedly increases the activity of dialyzed extracts. Sodium pyruvate does not affect the synthesis of acetylcholine by the bacterial enzyme; sodium fluoride acts as a potent inhibitor. The activity of the extract is at least twice that reported for purified mammalian brain preparations and is 45% as potent as the highly active squid head ganglion enzyme.