title: Heparin-acetylcholinesterase interaction: Specific detachment of class I-A forms and binding of class I and II-A forms to heparin-agarose.
abstract: This study describes the specificity, time-course and characteristics of the solubilization of class I-A forms of AChE by heparin, from the endplate regions of rat diaphragm muscle. Heparin fractions which differed in size charge, anticoagulant activity and capacity to bind type I collagen, were probed in their ability to extract AChE. No differences were found among all the fractions tested. Affinity chromatography on heparin-agarose of class I- and class II-A forms of esterase showed that both classes were able to bind to the column with the same relative affinity. Our results establish the use of heparin, as a solubilizing agent for the class I-A. The existence of a heparin-binding domain in class I- and class II-A forms of AChE, opens the possibility, that heparan sulfate proteoglycans could be involved in the anchorage of both types of esterase to synaptic regions. Finally, our results suggest that class I and class II-A do not correspond to intrinsically distinct molecules, but rather to identical molecules engaged in different interactions in the tissue.
authors.affiliation: Group of Molecular Neurobiology, Laboratory of Neurophysiology, Department of Cell Biology, Catholic University of Chile, P.O. Box 114-D, Santiago, Chile.
authors.forename: E
authors.initials: E
authors.lastname: Brandan
authors.forename: I
authors.initials: I
authors.lastname: Llona
authors.forename: N C
authors.initials: NC
authors.lastname: Inestrosa