Comparison of the subunit structure of acetylcholine receptors from muscle and electric organ of Electrophorus electricus

Biochemistry ◽  
1983 ◽  
Vol 22 (16) ◽  
pp. 3801-3807 ◽  
Author(s):  
W. J. Gullick ◽  
J. M. Lindstrom
Keyword(s):  
Acetylcholine Receptors ◽  
Electric Organ ◽  
Subunit Structure ◽  
Electrophorus Electricus

Purification of acetylcholine receptors from the muscle of Electrophorus electricus

Biochemistry ◽  
1983 ◽  
Vol 22 (16) ◽  
pp. 3796-3800 ◽  
Author(s):  
J. M. Lindstrom ◽  
J. F. Cooper ◽  
L. W. Swanson
Keyword(s):  
Acetylcholine Receptors ◽  
Electrophorus Electricus

Molecular Cloning and Expression of a Kv1.1-like Potassium Channel from the Electric Organ of Electrophorus electricus

2003 ◽  
Vol 196 (1) ◽  
pp. 1-8 ◽  
Author(s):  
W. B. Thornhill ◽  
I. Watanabe ◽  
J. J. Sutachan ◽  
M. B. Wu ◽  
X. Wu ◽  
...  
Keyword(s):  
Potassium Channel ◽  
Molecular Cloning ◽  
Electric Organ ◽  
Cloning And Expression ◽  
Electrophorus Electricus

scholarly journals The molecular form of acetylcholinesterase as determined by irradiation inactivation (Short Communication)

1974 ◽  
Vol 137 (1) ◽  
pp. 123-125 ◽  
Author(s):  
S. R. Levinson ◽  
J. C. Ellory
Keyword(s):  
Molecular Weight ◽  
Short Communication ◽  
Molecular Form ◽  
Electric Organ ◽  
Molecular Size ◽  
Erythrocyte Ghosts ◽  
Multiple Forms ◽  
Electrophorus Electricus ◽  
Membrane Bound

The molecular size of acetylcholinesterase (EC 3.1.1.7) from the electric organ of Electrophorus electricus and erythrocyte ‘ghosts’ was estimated in both membrane-bound and purified preparations by irradiation inactivation. Results suggest that the form of the enzyme in the membrane is a monomer of molecular weight approx. 75000 and that multiple forms of the enzyme observed in solubilized preparations are aggregates of this monomer.

scholarly journals Interactions of Nereistoxin and Its Analogs with Vertebrate Nicotinic Acetylcholine Receptors and Molluscan ACh Binding Proteins

Marine Drugs ◽  
2022 ◽  
Vol 20 (1) ◽  
pp. 49
Author(s):  
William Kem ◽  
Kristin Andrud ◽  
Galen Bruno ◽  
Hong Xing ◽  
Ferenc Soti ◽  
...  
Keyword(s):  
Disulfide Bond ◽  
Nicotinic Acetylcholine Receptors ◽  
Acetylcholine Receptors ◽  
Specific Radioactivity ◽  
Electric Organ ◽  
Binding Affinities ◽  
Nicotinic Acetylcholine ◽  
High Affinity ◽  
High Specific Radioactivity ◽  
Alpha Bungarotoxin

Nereistoxin (NTX) is a marine toxin isolated from an annelid worm that lives along the coasts of Japan. Its insecticidal properties were discovered decades ago and this stimulated the development of a variety of insecticides such as Cartap that are readily transformed into NTX. One unusual feature of NTX is that it is a small cyclic molecule that contains a disulfide bond. In spite of its size, it acts as an antagonist at insect and mammalian nicotinic acetylcholine receptors (nAChRs). The functional importance of the disulfide bond was assessed by determining the effects of inserting a methylene group between the two sulfur atoms, creating dimethylaminodithiane (DMA-DT). We also assessed the effect of methylating the NTX and DMA-DT dimethylamino groups on binding to three vertebrate nAChRs. Radioligand receptor binding experiments were carried out using washed membranes from rat brain and fish (Torpedo) electric organ; [3H]-cytisine displacement was used to assess binding to the predominantly high affinity alpha4beta2 nAChRs and [125I]-alpha-bungarotoxin displacement was used to measure binding of NTX and analogs to the alpha7 and skeletal muscle type nAChRs. While the two quaternary nitrogen analogs, relative to their respective tertiary amines, displayed lower α4β2 nAChR binding affinities, both displayed much higher affinities for the Torpedo muscle nAChR and rat alpha7 brain receptors than their respective tertiary amine forms. The binding affinities of DMA-DT for the three nAChRs were lower than those of NTX and MeNTX. An AChBP mutant lacking the C loop disulfide bond that would potentially react with the NTX disulfide bond displayed an NTX affinity very similar to the parent AChBP. Inhibition of [3H]-epibatidine binding to the AChBPs was not affected by exposure to NTX or MeNTX for up to 24 hr prior to addition of the radioligand. Thus, the disulfide bond of NTX is not required to react with the vicinal disulfide in the AChBP C loop for inhibition of [3H]-epibatidine binding. However, a reversible disulfide interchange reaction of NTX with nAChRs might still occur, especially under reducing conditions. Labeled MeNTX, because it can be readily prepared with high specific radioactivity and possesses relatively high affinity for the nAChR-rich Torpedo nAChR, would be a useful probe to detect and identify any nereistoxin adducts.

scholarly journals Identification of agrin, a synaptic organizing protein from Torpedo electric organ.

1987 ◽  
Vol 105 (6) ◽  
pp. 2471-2478 ◽  
Author(s):  
R M Nitkin ◽  
M A Smith ◽  
C Magill ◽  
J R Fallon ◽  
Y M Yao ◽  
...  
Keyword(s):  
Acetylcholine Receptors ◽  
Neuromuscular Junctions ◽  
Gel Filtration ◽  
Electric Organ ◽  
Molecular Characteristics ◽  
Active Components ◽  
Cultured Myotubes ◽  
Aggregation Activity ◽  
Two Peaks

Extracts of the electric organ of Torpedo californica contain a proteinaceous factor that causes the formation of patches on cultured myotubes at which acetylcholine receptors (AChR), acetylcholinesterase (AChE), and butyrylcholinesterase (BuChE) are concentrated. Results of previous experiments indicate that this factor is similar to the molecules in the synaptic basal lamina that direct the aggregation of AChR and AChE at regenerating neuromuscular junctions in vivo. We have purified the active components in the extracts 9,000-fold. mAbs against four different epitopes on the AChR/AChE/BuChE-aggregating molecules each immunoprecipitated four polypeptides from electric organ extracts, with molecular masses of 150, 135, 95, and 70 kD. Gel filtration chromatography of electric organ extracts revealed two peaks of AChR/AChE/BuChE-aggregation activity; one comigrated with the 150-kD polypeptide, the other with the 95-kD polypeptide. The 135- and 70-kD polypeptides did not cause AChR/AChE/BuChE aggregation. Based on these molecular characteristics and on the pattern of staining seen in sections of muscle labeled with the mAbs, we conclude that the electric organ-aggregating factor is distinct from previously identified molecules, and we have named it "agrin."

Effect of denervation on the glycolytic metabolism of the main electric organ of Electrophorus electricus (L.)

1985 ◽  
Vol 81 (4) ◽  
pp. 969-973
Author(s):  
Jeanette Torres-da Matta ◽  
Célia B.E. Silva ◽  
Arthur Nery da Matta ◽  
Aída Hassón-Voloch
Keyword(s):  
Electric Organ ◽  
Glycolytic Metabolism ◽  
Electrophorus Electricus
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