Overview
- Olianas, M.C. et al. (2000) Br. J. Pharmacol. 131, 447.
It is recommended to prepare fresh solutions in working buffers before use, or aliquot stock solutions reconstituted in distilled water and keep at -20°C. Upon use, dilute the stock solution in the desired working buffer. Prevent repeated thawing and freezing cycles. Centrifuge all product preparations before use (10000 x g 5 min).
![Alomone Labs Muscarinic Toxin 7 inhibits Carbachol-evoked [Ca2+]in increase in M1R-expressing C6 cells.](https://assets.alomone.com/wp-content/uploads/2019/02/STM-200_gr.gif)
Alomone Labs Muscarinic Toxin 7 inhibits Carbachol-evoked [Ca2+]in increase in M1R-expressing C6 cells.Cells were loaded with Fluo-3 AM and pre-incubated for 20 min with control or with 25 nM and 100 nM Muscarinic Toxin 7 (#STM-200), as indicated, and stimulated with 100 µM Carbachol (arrow). Changes in intracellular Ca2+ were detected as changes in Fluo-3 emission following stimulation.
- Olianas, M.C. et al. (2000) Br. J. Pharmacol. 131, 447.
The action of the neurotransmitter acetylcholine (Ach) is mediated through two types of receptors, the ionotropic nicotinic receptors and the metabotropic muscarinic receptors. The muscarinic receptors belong to the superfamily of G-protein coupled receptors. Five subtypes of muscarinic receptors have been cloned: m1-m51,2.
The muscarinic receptors are widely distributed throughout the body, but are predominantly expressed within the parasympathetic nervous system and exert both excitatory and inhibitory control over central and peripheral tissues1,2.
Muscarinic receptors participate in a number of physiological functions such as regulation of heart rate, muscle contraction, cognition, sensory processing and motor control1. They also participate in learning and memory processing3,4.
Muscarinic Toxin 7 is a 65 amino acid peptide toxin isolated from the Dendroaspis angusticeps (Eastern green mamba)5. It was first found to inhibit M1 muscarinic receptors stably transfected in CHO cells at very low concentrations (1-30 nM)6 and acts as a non-competitive antagonist by binding to an allosteric site6.
Muscarinic Toxin 7 binding studies using a M1 and M3 chimera demonstrated that the high affinity of Muscarinic Toxin 7 towards M1 receptor is due to only three residues located in the 2nd and 3rd extracellular loops of the receptor7.
