Coordination of iron ions with phycocyanin for an improved Fenton activity at weakly acidic pH
Yixin Xing1, Jingyi Li1, Yuanjie Fan1
1School of Pharmaceutical Sciences, Capital Medical University, Beijing 100069, PR China.
Abstract:
Development of biomolecules coordinated iron ions-based Fenton agents is highly desirable for chemodynamic therapy in term of demanded biocompatibility and enhanced Fenton activity at tumor microenvironmental pH of 6.5. Herein, phycocyanin (PC), the only FDA-approved natural coloring agent, was selected to coordinate with iron ions. The spectroscopic investigations disclosed that PC displayed pH-dependent spectral and conformational responses upon addition of Fe ions. As a result, the effective formation of Fe-PC coordination merely occurred at pH 7 due to a less folded polypeptide matrix of PC. The formed Fe-PC coordination exerted an enhanced Fenton activity at pH 6.5 as attested by 3, 3', 5, 5'-tetramethlbenzidine assay and steady-state kinetic analysis. These findings not only provide fundamental insights of Fe-PC coordination but also highlight the potential biomedical significance of Fe-PC for severing as an effective Fenton agent in chemodynamic therapy.
Related Concept Videos
Colors and Magnetism
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
Extraction: Advanced Methods
Factors Affecting Solubility
Metal-Ligand Bonds
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
Formation of Complex Ions
EDTA: Chemistry and Properties


