THE ELECTRIC ORGAN OF DISCOPYGE-TSCHUDII - ITS INNERVATED FACE AND THE BIOLOGY OF ACETYLCHOLINESTERASE
No Thumbnail Available
Date
1984
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
An ultrastructural, histochemical and biochemical study of the electric organ of the South American Torpedinid ray. D. tschudii was carried out. Fine structural cytochemical localization of acetylcholinesterase (AChE) indicated that most of the esterase was associated with the basal lamina. EM indicated no marked differences in the electrocyte ultrastructure between Discopyge and Torpedo californica. Discopyge electric organ possessed 3 molecular forms, 2 asymmetric forms (16 S and 13 S) and 1 globular hydrophobic form (6.5 S). The asymmetric 16 S AChE form was solubilized by heparin, a sulfated glycosaminoglycan, suggesting that heparin-like macromolecules are involved in the binding of the enzyme to the basal lamina. Cell-free translated AChE peptides, synthesized using Discopyge electric organ poly(A+) RNA, correspond to a main band of 62,000 daltons which probably represents the catalytic subunit of the asymmetric AChE.