Main > PHYSIOLOGY > Porphyrins. > Synthetic Porphyrin.Ligand > Co. Org.: MU (Bind K Channel) > NPLS Contents

---

"We were prompted to develop our ligands by analyzing X-ray structures of potassium channels and their interactions with naturally occurring peptide toxins. In these channels, the pore that potassium ions go through is located at the center of symmetry of four identical protein subunits. So Author settled on tetraphenylporphyrins in the hopes that the fourfold symmetrical molecules might interact with all four subunits simultaneously. Such polyvalent ligands should bind to the extracellular side of the channel with high affinity, he tells. In fact, the water-soluble tetraphenylporphyrins that Author et al synthesized bind to voltage-gated potassium ion channels with nanomolar affinities. Porphyrins that bear phenyl groups with positively charged substituents are particularly good inhibitors of channel function--although none of the derivatives Author s team has tested completely blocks potassium ion flow across the membrane.

"The modular composition of our ligands allows easy modifications and should provide a large set of synthetic probes that discriminate among different potassium channels," the authors write. Author is particularly interested in making metalloporphyrins and fluorescent porphyrins with larger substituents. these ligands could be used to "dial in" channel specificity to selectively modulate the action of specific channels in vivo.




NPLS Contents's products
This section has no products