|
|
|
|
Molecular Pharmacology, Vol 10, 703-708, Copyright © 1974 by the American Society for Pharmacology and Experimental Therapeutics
1 Division of Pharmacology, Department of Medicine, University of California, San Diego,
La Jolla, California 92037
Propidium (3, 8-diamino-5, 3'-diethylmethylamino-n-propyl-6-phenylphenanthridium) diiodide binds with high affinity to a purified acetylcholinesterase isolated by lytic procedures from Torpedo californica. Complex formation results in 10-fold enhancement of
fluorescence for the ligand in the bound state. The fluorescent ligand can be dissociated
from the enzyme by back-titration with d-tubocurarine and gallamine under conditions of
low ionic strength (
/2
0.001). At higher ionic strength, in 0.1 M NaCl, 0.04 M MgCl2,
and 0.01 M Tris-Cl, pH 8.0 (
/2 = 0.23), the above ligands are relatively ineffective in
dissociating propidium from the enzyme. Edrophonium, an inhibitor that appears specific
for the active center, does not dissociate propidium under conditions of high and low ionic
strength. This specificity is consistent with propidium acting as a fluorescence probe for a
peripheral anionic site on acetylcholinesterase.
This article has been cited by other articles:
![]() |
H. M. Dodds and L. P. Rivory The Mechanism for the Inhibition of Acetylcholinesterases by Irinotecan (CPT-11) Mol. Pharmacol., December 1, 1999; 56(6): 1346 - 1353. [Abstract] [Full Text] |
||||
![]() |
C. Himel, J. Taylor, C Pape, D. Millar, J Christopher, and L Kurlansik Acridine araphanes: a new class of probe molecules for biological systems Science, September 21, 1979; 205(4412): 1277 - 1279. [Abstract] [PDF] |
||||
![]() |
G. V. De Ferrari, W. D. Mallender, N. C. Inestrosa, and T. L. Rosenberry Thioflavin T Is a Fluorescent Probe of the Acetylcholinesterase Peripheral Site That Reveals Conformational Interactions between the Peripheral and Acylation Sites J. Biol. Chem., June 22, 2001; 276(26): 23282 - 23287. [Abstract] [Full Text] [PDF] |
||||