Regular Article
Recombinant Expression of a Selective Blocker of M1 Muscarinic Receptors

https://doi.org/10.1006/bbrc.2000.2657Get rights and content

Abstract

Mamba venoms contain peptides with high selectivity for muscarinic receptors. Due to the limited availability of the M1 muscarinic receptor-selective MT7 or m1-toxin 1, the peptide was expressed in Sf9 cells using a synthetic cDNA and purified. The isolated peptide had over four orders of magnitude higher affinity for the M1 compared to M2–M5 muscarinic receptors. The peptide strongly inhibited Ca2+ mobilisation through recombinant and endogenously expressed M1 receptors, having no effect on the function of the other subtypes. The MT7 peptide provides a unique tool for identification and functional characterisation of M1 receptors in cells and tissues.

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