Intracellular Distribution of Choline Acetylase

WITH the development of methods for the measurement of choline acetylase independently of the enzymic formation of acetyl-coenzyme A 1–3 , it has become possible to determine the intracellular distribution of the enzyme. In the present experiments, rabbit brain homogenates in 0.25 M sucrose were fractionated by differential centrifugation. In exp. 1 the procedure of Brody and Bain 4 was followed; in exp. 2, somewhat different centrifugal forces were applied as shown in Table 1. Each particulate fraction was washed by resuspension in 0.25 M sucrose and recentrifugation at the same speed; the washings were then pooled with the original supernatant for the next stage of the centrifugation.