The Cu(II) affinity constant and reactivity of Hepcidin-25, the main iron regulator in human blood

• DOI: 10.1016/j.jinorgbio.2023.112364
• Publication Date: 2023-09-02T06:00:14Z
• Authors: Dawid Płonka; Marta D. Wiśniewska; Joanna Ziemska-Le...; Marcin Grynberg; Wojciech Bal
• Keywords: Binding constant

Hepcidin is an iron regulatory hormone that does not bind directly. Instead, its mature 25-peptide form (H25) contains a binding site for other metals, the so-called ATCUN/NTS (amino-terminal Cu/Ni site). The Cu(II)-hepcidin complex was previously studied, but due to poor solubility and difficult handling of peptide definitive account on equilibrium obtained reliably. In this study we performed series fluorescence competition experiments between H25 model peptides containing same determined Cu(II) conditional constant CuH25 at pH 7.4, CK7.4 = 4 ± 2 × 1014 M-1. This found be very inert in exchange reactions poorly reactive ascorbate consumption test. consequences these findings putative role interactions with are discussed.