[Large scale purification of the acetylcholinesterase from bovine caudate nucleus by affinity chromatography...

The acetylcholinesterase from bovine caudate nucleus was solubilized with 0.6-0.8% Triton X-100. It was purified and freed from Triton X-100 by means of a two-fold affinity chromatography procedure. A simple three-step synthesis of the inhibitor with attached spacer arm used in affinity chromatography is described. Starting from 3 kg of caudate nucleus, nearly 11 mg of the purified acetylcholinesterase with a spec. act of 4250 U/mg (13 500-fold purification) could be obtained in an over-all yield of 49%. On gel electrophoresis the enzyme produces several enzymatically active glycoproteinbands of oligomeres. On sodium dodecylsulfate gel electrophoresis in the presence of a disulfide-reducing agent it yields a molecular weight of 72000 +/- 2000 for the smallest subunit. In the absence of a disulfide-reducing agent a band for a dimer besides the band for the monomer could be detected and a molecular weight of 142000 +/- 3000 was estimated for this species.