Bioconjug Chem 2013 Sep 14;24(9):1527-32. Epub 2013 Aug 14.
Chemical Biology Group, Institute of Pharmaceutical Sciences, and ‡Nutrition and Diabetes Research Group, King's College London , Franklin-Wilkins Building, 150 Stamford Street, London SE1 9NH, U.K.
Hepcidin is a peptide hormone that regulates homeostasis in iron metabolism. It binds to the sole known cellular iron exporter ferroportin (Fpn), triggers its internalization, and thereby modulates the efflux of iron from cells. This functional property has been adopted in this study to assess the bioactivity and potency of a range of novel fluorescent hepcidin analogues. Hepcidin was selectively labeled with 6-carboxyfluorescein (CF) and 6-carboxytetramethylrhodamine (TMR) using Fmoc solid phase peptide chemistry. Internalization of Fpn by hepcidin was assessed by high-content microscopic analysis. Both K18- and M21K-labeled hepcidin with TMR and CF exhibited measurable potency when tested in cultured MDCK and T47D cells expressing human ferroportin. The bioactivity of the labeled hepcidin varies with the type of fluorophore and site of attachment of the fluorophores on the hepcidin molecule.