GLYCOSYLATION OF ACETYLCHOLINESTERASE FORMS IN MICROSOMAL-MEMBRANES FROM NORMAL AND DYSTROPHIC LAMA2(DY) MOUSE MUSCLE

The distribution and glycosylation of acetylcholinesterase (AChE) form s in vesicles derived from sarcoplasmic reticulum of normal muscle (NM V) were investigated and compared with those from dystrophic muscle ve sicles (DMV). AChE activity was similar in NMV and DMV. Most of the AC hE in NMV and half in DMV were released with Triton X-100. Asymmetric (A(12)) and globular hydrophilic and amphiphilic (G(4)(H), G(4)(A), G( 2)(A), and G(1)(A)) AChE species occurred in NMV and DMV, the lighter forms being predominant. The percentage of G(4)(H) and G(4)(A) decreas ed in DMV. A fraction of the AChE that could not be extracted with det ergent was detached with collagenase. Most of the detergent-released A (12) AChE from NMV and nearly half in DMV failed to bind to Ricinus co mmunis agglutinin (RCA-I), Conversely, the collagenase-detached isofor ms bound to RCA, revealing that asymmetric AChE associated with intern al membranes or basal lamina differed in glycosylation. Moreover, near ly half of G(4)(A) AChE in DMV and a few in NMV bound to RCA. Most of the RCA-unreactive G(4)(A) forms in NMV come from sarcolemma. The resu lts indicate that dystrophy induces minor changes in the distribution and glycosylation of AChE forms in internal membranes of muscle.