AMPHIPHILIC PROPERTIES OF MOLECULAR-FORMS OF ACETYLCHOLINESTERASE IN NORMAL AND DYSTROPHIC MUSCLE

Acetylcholinesterase (AChE) molecular forms were studied in normal (NM) and in dystrophic (DM) 129B6F(1)/J mouse muscle. Successive extractions of the tissue with saline and saline-Triton X-100 buffers yielded two soluble fractions, S-1 and S-2. Forty percent of the AChE in NM was measured in S-1 and 60% in S-2, and 65% and 35%, respectively, in extracts from DM. A(12), A(8), G(4), G(2), and G(1) forms of AChE were found in S-1 and S-2 from NM and DM. A similar content of asymmetric molecules was noticed between NM and DM. G(4) AChE was a minor species in DM, and G(1) and G(2) AChE were more abundant in DM than in NM. The amphiphilic properties of the several molecules were assessed by Triton X-114 phase-partitioning and hydrophobic chromatography. Thirty and 70% of the enzyme in a mixture of S-1 and S-2 partitioned in the detergent-rich and in the detergent-poor phases, respectively, whether the extracts were obtained from NM or DM. Asymmetric and G(4) AChE predominated in the aqueous phase and G(1) and G(2) in the detergent phase. Ten and 25% of the enzyme in S-1 from NM or DM, respectively, was adsorbed to the phenyl-agarose. Elution of the retained enzyme followed by sedimentation analysis revealed that a certain amount of asymmetric and most of the G(1) and G(2) forms were associated with the matrix. The content of amphiphilic asymmetric and light globular forms was notably higher in DM than in NM. The results suggest that dystrophic muscle produces a specific pattern of molecular forms of AChE. (C) 1994 Wiley-Liss, Inc.