title: Multiple forms of acetylcholinesterase from human erythrocytes.
abstract: 1. Acetylcholinesterase from human erythrocytes was solubilized with Triton X-100 in strong salt solution and partially purified by (NH(4))(2)SO(4) fractionation. This preparation showed three main bands of enzyme activity after electrophoresis on polyacrylamide gel and incubation with either alpha-naphthyl acetate or acetylthiocholine as enzyme substrate. Two of the multiple forms were completely inhibited by 10mum-eserine and one only partially. Treatment with neuraminidase had no effect on the electrophoretic pattern; therefore sialic acid does not appear to determine or affect the ratios of the acetylcholinesterase multiple forms, unlike those of the serum cholinesterase. 2. Chromatography of the preparation on Sephadex G-200 revealed one major peak of enzyme activity and a suggestion of two minor zones of mol.wt. 546000, 184000 and 93000 (i.e. in the proportion 6:2:1). The main peak was almost completely separated from the Triton X-100 and the overall purification was about 600-fold. Further attempts to purify the enzyme by absorption on calcium phosphate gels were unsuccessful. 3. Electrophoresis of the enzyme preparation on a polyacrylamide gradient for 24h revealed three main bands that corresponded to the three values for molecular weights obtained by column chromatography. After 70h of electrophoresis a further three zones of activity developed making six molecular entities, the molecular weights of which were simple multiples of a monomer, thus resembling the cholinesterase found in serum.
mesh_terms: D000085:Acetates; D000109:Acetylcholine; D000110:Acetylcholinesterase / Q000302:isolation & purification*; D002130:Calcium Phosphates; D002623:Chemistry Techniques, Analytical; D002802:Cholinesterases / Q000097:blood; D002845:Chromatography; D002850:Chromatography, Gel; D004589:Electrophoresis, Disc; D004591:Electrophoresis, Polyacrylamide Gel; D004912:Erythrocytes / Q000201:enzymology*; D005782:Gels; D006801:Humans; D007527:Isoenzymes / Q000302:isolation & purification*; D008722:Methods; D008970:Molecular Weight; D009281:Naphthalenes; D009439:Neuraminidase; D010830:Physostigmine; D011134:Polysaccharides; D013501:Surface-Active Agents
chemical_list: D000085:Acetates; D002130:Calcium Phosphates; D005782:Gels; D007527:Isoenzymes; D009281:Naphthalenes; D011134:Polysaccharides; D013501:Surface-Active Agents; D010830:Physostigmine; D000110:Acetylcholinesterase; D002802:Cholinesterases; D009439:Neuraminidase; D000109:Acetylcholine