Molecular tools for the NPY Y receptor: Fluorescence- and radiolabelled [Lys,Nle1]hPP

Previously, the fluorescent peptide Cy5-[Lys4]hPP (Kd=5.6nM) was synthesized in our laboratory for the investigation of the Y4 receptor (Y4R) in living cells (Ziemek et al., 2007). To preclude methionine oxidation, resulting in mixtures of products during storage, and with respect to the synthesis of an improved fluorescent and a newradiolabelled ligand, we replaced the two methionine residues in[Lys4]hPP by norleucine ([Lys4,Nle17,30]hPP). Radiolabelling gave [3H]propionyl-[Lys4,Nle17,30]hPP. This tritiated peptide revealed a Kd value of 5.9nM and very low non-specific binding (at 5nM: 10 % of total binding; CHO cells expressing the hY4R), and proved to be a useful tool for the determination of binding sites and Ki values.

Source: Neuropeptides - February 1, 2016 Category: Neuroscience Authors: Stefanie Dukorn, Max Keller, Kilian Kuhn, Chiara Cabrele, Günther Bernhardt, Armin Buschauer Source Type: research