Tripodal polypeptides

Fig. 6.6 Tripodal polypeptide subject to allosteric control by Zn(ll) ions for the cleavage of RNA substrates [45]. The catalytic site with three Zn(ll) ions is the active species with HPNP, while the most active species with RNA is that devoid of metal ions...

Research by P. Scrimin and U. Toneiiato et ai. showed that Zn " was an aiiosteric reguiator of liposomal membrane permeability induced by synthetic template-assembled tripodal polypeptides. Several copies of peptide sequences from the peptaibol family were connected to fr/s(2-aminoethyl)amine (TREN), which is a tripodal metal ion ligand. The resulting tripodal polypeptides were capable of modifying the permeability of liposomal membranes, and their activity was tunable upon metal ion coordination of the TREN subunit. The synthesis of the TREN-based template began with the Stephen reduction of 4-cyanomethylbenzoate followed by the reductive amination of the resulting aldehyde with TREN. 

Scrimin, P., Tecilla, P., Tonellato, U., Veronese, A., Crisma, M., Formaggio, F., Toniolo, C. Zinc(ll) as an allosteric regulator of liposomal membrane permeability induced by synthetic template-assembled tripodal polypeptides. Chem.-Eur. J. 2002, 8, 2753-2763. 

Fig. 3 Tripodal polypeptide used as a biomimetic supramolecular catalyst for the cleavage of phosphate esters. The tien platform is an allosteric control site. (View this art in color at www.dekker.com.)...

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