Title: Choline Esterase
CAS Registry Number: 9001-08-5
Literature References: There are at least two choline esterases. Acetylcholinesterase is a "specific" choline esterase, hydrolyzing predominantly choline esters, and characterized by high concns in brain, nerve and red blood cells. The other type, called butyrylcholinesterase, is a nonspecific choline esterase ("pseudo" choline esterase), hydrolyzing other esters as well as choline esters, and found in blood serum, pancreas and liver, cf. Sumner and Somers, Chemistry and Methods of Enzymes (New York, 1947). Prepn from dog pancreas: Mendel, Mundell, Biochem. J. 37, 64 (1943); from horse serum: Strelitz, ibid. 38, 86 (1944). Reviews: Davies, Green, Adv. Enzymol. 20, 283 (1958); Froede, Wilson, "Acetylcholinesterase" in The Enzymes vol. 5, P. D. Boyer, Ed. (Academic Press, N. Y., 3rd ed., 1971) pp 87-114.
Properties: Specific choline esterase develops its max activity at pH 7 and at low levels of acetylcholine (less than 2.5 mg %). Both enzymes are inhibited by very small quantities of physostigmine (eserine). Acetylcholinesterase is inhibited by phosphorus-containing insecticides and nerve gases.