The preparation of soluble cholinesterases from mammalian heart and brain

Abstract

Soluble prepns. of cholinesterases from rat heart and brain were obtained, the enzyme from heart being purified approx. 30-fold and the brain enzyme approx. 10-fold. Specificity and inhibition studies on the heart prepn. revealed the presence of at least 2 cholinesterases and an ali-esterase. The cholinesterase present in greatest amount exhibited certain differences from both the true and pseudo-cholinesterases described hitherto. The effect of 20 surface-active substances on the extraction and activity of rat brain cholinesterase were studied; Eleven of 14 ionic surface-active substances caused a complete or almost complete inhibition of activity, whereas all 6 non-ionic substances left the activity unimpaired. The mechanism of the "solubilizing" action of certain of these surface-active agents on the brain enzyme was discussed.