Interaction of heparin with multimolecular aggregates of acetylcholinesterase.

It has been reported previously that heparin, a sulfated glycosaminoglycan, releases the asymmetric 16 S form of acetylcholinesterase (AChE) from cholinergic synapses. Here it is shown that heparin releases the synaptic AChE not as individual 16 S species but as multimolecular aggregates (30 S) of such molecules. Heparin is able to convert low-ionic strength AChE aggregates into a heparin type of AChE aggregates. Our results suggest that the AChE aggregates detached by heparin are likely to be the physiologically important state of aggregation of the 16 S AChE form in the synaptic basal lamina.