Investigation on the interaction between Ag⁺ and bovine hemoglobin using spectroscopic methods

Abstract

Silver ions (Ag⁺) can be released by silver nanoparticles (AgNPs) which are widely used in diverse fields. Ag⁺ can exist inside cells to produce cytotoxicity. This report uses spectroscopic methods to reveal the interactions between Ag⁺ and bovine hemoglobin (BHb). The results of the quenching rate constant (K_q) and the fluorescence lifetime detection showed that the quenching mechanism of BHb by Ag⁺ was static. Thermodynamic investigations indicated that Ag⁺ can interact with BHb with one binding site to form complex mainly through van der Waals interactions and hydrogen bonds. The UV-vis absorption and synchronous fluorescence spectra showed that Ag⁺ changed the conformation of BHb, which may affect protein functions. This research is favorable for understanding the molecular toxic mechanism of Ag⁺ in vivo.

Keywords:

• Silver ions
• bovine hemoglobin
• fluorescence quenching mechanism
• binding parameter
• conformation

Data availability statement

The data that support the findings of this study are available from the corresponding author, Zhenxing Chi, upon reasonable request.

Additional information

Funding

This work was supported by the National Science Foundation of China (21707026), the Natural Science Foundation of Shandong Province (ZR2014BQ033), and the Guangzhou Key Laboratory of Environmental Exposure and Health (No. GZKLEEH201613).