Synthetic Receptors for the Differentiation of Phosphorylated Peptides with Nanomolar Affinities

Abstract

Artificial ditopic receptors for the differentiation of phosphorylated peptides varying in i+3 amino acid side chains were synthesized, and their binding affinities and selectivities were determined. The synthetic receptors show the highest binding affinities to phosphorylated peptides under physiological conditions (HEPES, pH 7.5, 154 mM NaCl) reported thus far for artificial systems. The tight and selective binding was achieved by high cooperativity of the two binding moieties in the receptor molecules. All receptors interact with phosphorylated serine by bis(ZnII-cyclen) complex coordination and a second binding site recognizing a carboxylate or imidazole amino acid side chain functionality.

Binding of phosphorylated peptides and inhibition of their interaction with disease‐relevant human proteins by synthetic metal‐chelate receptors

“…In peptide 3 only the phosphate group is a suitable binding partner for receptors 5 and 6 as bis-zinc(II)-cyclen triazine shows no measurable affinity to carboxylates (Grauer et al, 2008).…”

“…The determined affinities were exemplarily verified by fluorescence polarization titrations as an independent method (Grauer et al, 2008). Binding stoichiometries were determined by Job's plot analysis and were found to be 1:1 in all cases.…”

“…We have previously reported that bis-zinc(II)-cyclen triazine 18 employed as one of the two binding sites in the synthetic receptors coordinates to phosphorylated amino acids under physiological conditions (Grauer et al, 2008). With lower affinity, this moiety also binds to histidine residues.…”

“…(Pandey et al, 2000a, b;Machida et al, 2007;Manning et al, 2002a, b;Steen et al, 2002;Yeung et al, 1998) The binding selectivity and affinity of metal complex binding sites is enhanced if they are combined with functional groups that allow (www.interscience.wiley.com) DOI:10.1002/jmr.986 Research Article for additional specific interactions with the target peptide sequence. We have recently used such ditopic metal complex based receptors for the discrimination of phosphorylated peptides with nanomolar affinities (Grauer et al, 2008).…”

Luminescent Hybrids Combining a Metal Complex and a Crown Ether – Receptors for Peptidic Ammonium Phosphates

“…[27][28][29][30] A comprehensive review on the molecular interactions of Zn II -cyclene and its derivatives has recently been published. [31] Zn II -dipicolylamine-stilbazoles have been shown to bind to a natural phosphoprotein recognition domain.…”