Application of transition metal ions in a study of photoinduced modifications of melanin
1Department of Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland.
Abstract:
Short wavelength visible light is viewed as the main agent responsible for oxidative modification of melanin in the human retinal pigment epithelium (RPE). The aim of this research was to study light-induced modifications of melanin using iron and zinc as molecular probes. A synthetic model of eumelanin was treated by intense violet light. The interaction of melanin with metal ions was examined by electron paramagnetic resonance (EPR) spectroscopy and a thiocyanate assay. Weak photodegradation of melanin was shown to increase exposure of melanin subunits, while stronger photodegradation caused a loss of melanin subunits. Iron-binding in such melanin was weak and nonspecific.
Related Concept Videos
Properties of Transition Metals
Formation of Complex Ions
Ions and Ionic Charges
Phase Transitions
Bonding in Metals
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...


