Torpedo marmorata

Heidmann, T. Oswald, R.E. and Changeux, J.-P. Multiple sites of action for noncompetitive blockers on acetylcholine receptor rich membrane fragments from Torpedo marmorata. Biochemistry 22 3112-3127, 1983. 

Lipid-protein interactions are of major importance in the structural and dynamic properties of biological membranes. Fluorescent probes can provide much information on these interactions. For example, van Paridon et al.a) used a synthetic derivative of phosphatidylinositol (PI) with a ris-parinaric acid (see formula in Figure 8.4) covalently linked on the sn-2 position for probing phospholipid vesicles and biological membranes. The emission anisotropy decays of this 2-parinaroyl-phosphatidylinositol (PPI) probe incorporated into vesicles consisting of phosphatidylcholine (PC) (with a fraction of 5 mol % of PI) and into acetylcholine receptor rich membranes from Torpedo marmorata are shown in Figure B8.3.1. 

Griinhagen HH, Iwatsubo M, Changeux JP. 1977. Fast kinetic studies on the interaction of cholinergic agonists with the membrane-bound acetylcholine receptor from Torpedo marmorata as revealed by quinacrine fluorescence. Fur J Biochem 80 225-242. 

True Cholinesterase from the Electric Organs of Eleclrophorus electricus or Torpedo marmorata... 

In this respect, the most important information has been obtained from the effect of pH changes on enzymic activity. In Fig. 2 the pH-activity curves are represented for true cholinesterase (from Torpedo marmorata) and pseudo-ChE (from human serum), with ACh as substrate. The two curves are not only similar to each other, but also to the curves, characteristic for other, unspecific esterases (37). For the correct interpretation of such curves, it is important to make sure that only the protein in the... 

Hughes, G.M. and Johnston, I.A. (1978). Some responses of the electric ray (Torpedo marmorata) to low ambient oxygen tensions. Journal of Experimental Biology 73, 107-117. 

The torpedo (Torpedo marmorata, also known as the electric ray) has an electric organ, rich in acetylcholine receptors, that can deliver a shock of as much as 200 V for approximately 1 s. [Yves Gladu/Jacana/ Photo Researchers.]... 

The nicotinic receptor has been successfully isolated from the electric ray (Torpedo marmorata) found in the Atlantic Ocean and Mediterranean sea, allowing the receptor to be carefully studied. As a result, a great deal is known about its structure and operation. 

Changeux, J, P. (1966). Responses of acetylcholineslcra.se from Torpedo marmorata to salts and curarizing agents. Mol Pharmacol 2,369-392. 

Raeber, A., et al. (1989). Purification and Isolation of Choline Acetyltransferase from the Electric Organ of Torpedo marmorata by Affinity Chromatography, Eur. J. Biochem. 186 487-492. 

Electric eel (Electrophorus electricus) (left) and marbled electric ray (Torpedo marmorata) (right). 

Butikofer, P., Kuypers, F. A., Shackleton, C. et al. (1990) Molecular species analysis of the glycosylphosphatidylinositol anchor of Torpedo marmorata acetylcholinesterase. J. Biol Chem., 265(31), 18983-7. 

Abstract - The crucial details for the interpretation of spatial structures and intermolecular interactions of peptides and proteins could be revealed by proper combination of physical and chemical techniques. The paper presents the results of the combined approach for the evaluation of the conformation in solution of honey-bee venom component apamin (18 membered polypeptide), of three dimensional structure of Central Asian cobra neurotoxin II (61 amino acid residues), and of the topography of its binding site with acetylcholine receptor Torpedo Marmorata. 

The interaction of selectively spin and dansyl mono-labeled neurotoxin II derivatives with solubilized nicotinic AChR protein isolated from Torpedo marmorata electric organ, was monitored by EPR and fluorescence spectroscopy(42). All the compounds specifically bind to the AChR, with dissociation constants ranging from 3 to 80 nM. The stoichiometry of the toxin-AChR complex is 2 1, assuming a molecular weight of 250 000 daltons for AChR(51). The two binding sites were found to be independent and indiscernible by dissociation constants and neurotoxin II spin label microenvironment, however they were not identical in that the nontoxic hexatrifluoro-acetyl neurotoxin II interacts only with one AChR binding site. 

Acetylcholine receptor protein from the electric organ of Torpedo marmorata was isolated by the procedure of reference(59). 

Marsh, D.,and Barrantes, F.J., 1978, Immobilized lipid in acetylcholine receptor-rich membranes from Torpedo Marmorata, Proc. Natl. Acad. Sci. USA, 75 4329. 

Kato, G., and J.-P. Changeux Studies on the effect of histrionicotoxin on the monocellular electroplax from Electrophorus electricus and on the binding of pH]-acetylcholine to membrane fragments from Torpedo marmorata. Mol. Pharmacol. 12, 92—100 (1976). 

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