Acetylcholinesterase: Affinity Techniques - Enzyme Purification: Part B

Publisher Summary Acetylcholinesterase (EC 3.1.1.7) (ACHE) is widely distributed in excitable membranes of nerve and muscle. Its molecular properties are of interest because of its involvement in nervous transmission. Most of the work on the molecular structure of AChE has utilized enzyme purified from the electric organ of the electric eel, Electrophorus electricus. This organ, because of its highly specialized function, contains relatively large amounts of ACHE. However, even in the electric organ there is only about 50–70 mg of enzyme per kilogram of wet tissue, whereas in other tissues the amounts of enzyme seem to be much lower if the same specific activity is assumed for AChE from different sources. Obviously, the application of affinity chromatography to the purification of AChE is desirable. The use of affinity chromatography in the purification of AChE was introduced by Kalderon. AChE is present in salt extracts of fresh or frozen electric organ tissue as three main components, which can be distinguished by their sedimentation coefficients on sucrose gradient centrifugation at high ionic strength.