POLYMORPHISM OF ACETYLCHOLINESTERASE AND IDENTIFICATION OF NEW MOLECULAR-FORMS AFTER SEDIMENTATION ANALYSIS

Acetylcholinesterase (AChE) is composed of several distinct molecular forms, which are identified and partly resolved by velocity sedimentation analysis on sucrose gradients. The assumption was made that each AChE form sediments as a peak of activity with a gaussian shape in the continuous sucrose gradient. The complex AChE profiles can be decomposed in gaussian distributions of separate molecular entities. A high salt-detergent extraction of AChE from mouse skeletal muscle was performed and isolated fractions were enriched in each particular form. These fractions were then submitted to a 2nd sedimentation, to assess the stability and to further characterize each AChE form. The statistical significance level of each AChE form was calculated and identified up to 9 separate molecular specifies in mouse adult muscle. These forms are the major 4 S, 6.5 S, 10 S, 12 S and 16 S and minor molecular active components of AChE. These results suggest complex structural interactions between catalytic and noncatalytic subunits of AChE and do not simply fit the tailed asymmetric globular model of AChE with 6 molecular species.