A major portion of synaptic basal lamina acetylcholinesterase is detached by high salt- and heparin-containing buffers from rat diaphragm muscle and Torpedo electric organ

Casanueva, OI; Garcia-Huidobro, T; Campos, EO; Aldunate, R; Garrido, J; Inestrosa, NC

Abstract

Collagen-tailed asymmetric acetylcholinesterase (AChE) forms are believed to be anchored to the synaptic basal lamina via electrostatic: interactions involving proteoglycans. However, it was recently found that in avian and rat muscles, high ionic strength or polyanionic buffers could not detach AChE: from cell-surface clusters and that these buffers solubilized intracellular non-junctional asymmetric AChE rather than synaptic: forms of the enzyme. In the present study, asymmetric AChE forms were specifically solubilized by ionic buffers from sg synaptic basal! lamina-enriched fractions, largely devoid of intracellular material, obtained from the electric organ of Torpedo californica and the end plate regions of rat diaphragm muscle, Furthermore, foci of AChE activity were seen to diminish in size, number, and staining intensity when the rat synaptic basal lamina-enriched preparations were treated with the extraction buffers, Pn the case of Torpedo, almost all the AChE activity was removed from the pure basal lamina sheets. We therefore conclude that a major portion of extracellular collagen-tailed AChE is extractable from rat and Torpedo synaptic basal lamina by high ionic strength and heparin buffers,;although some non-extractable AChE activity remains associated with the junctional regions.

Más información

Título según WOS: ID WOS:000072048400066 Not found in local WOS DB
Título de la Revista: JOURNAL OF BIOLOGICAL CHEMISTRY
Volumen: 273
Número: 7
Editorial: Elsevier
Fecha de publicación: 1998
Página de inicio: 4258
Página final: 4265
DOI:

10.1074/jbc.273.7.4258

Notas: ISI