The interaction of Yersinia pestis (YpHmuT) with Fe center on hemin (ferric form) or heme (ferrous form) was investigated by differential pulse voltammetry (DPV), cyclic voltammetry (CV), square wave voltammograms (SWV), electrochemical impedance spectroscopy (EIS) and spectra. Electrochemical signals of hemin/heme were strongly influenced by virtue of interacting with YpHmuT. The 2:1 stoichiometric ratio of the hemin or heme to YpHmuT was confirmed. YpHmuT binds to ferric hemin with penta-coordinate and high-spin and binds to ferrous heme with low-spin. Our findings may provide useful data for understanding biological processes of hemin transportation in Yersinia pestis. (C) 2019 Elsevier Ltd. All rights reserved.