This article is meant to rectify some earlier suggestions in my previous articles. In previous articles of mine, I have described melanin’s role in mitochondria health as being a battery for electrons due to its redox properties. This article is meant to shift that hypothesis towards a different idea: melanin is not a battery but a more advanced version of chlorophyll in the sense that it takes in light and produces electrons for mitochondrial use.

The core hypothesis here is that melanin is capable of chelation with metals, and this allows it to utilize light to split water molecules into hydrogen, oxygen, and electrons. Decades of research validates the idea that melanin contains binding sites with metals, such as copper, zinc, and iron (Sarna, Froncisz, and Hyde 1980; Szpoganicz et al. 2002; Double et al. 2003). Chelation occurs when a molecule binds to a metal ion through multiple attachment sites at once. Due to the binding occurring at multiple points, it wraps around the metal like a claw, creating a closed ring structure.

This ring structure with a metal in the center is like the chemical structure of chlorophyll and hemoglobin, and is likely the reason for melanin’s semi-conductor properties. As early as 1974, researchers began to notice that melanin conducted electricity and acted as a semi-conductor (McGinness, Corry, and Proctor 1974). By 2012, it was found that natural melanin’s conductive properties were made possible in the presence of water (Mostert et al. 2012). Later it was found that the oxidation potentials and enhancing redox features are enhanced when melanin chelates with iron and is exposed to water (Xu, Soavi, and Santato 2019). Furthermore, research has shown that shorter wavelength UV light is retained by melanin for longer periods than longer wavelength UV light (Forest and Simon 1998).

All this research in aggregate suggest that melanin’s ability to chelate with metals and form rings that can absorb light will excite electrons for the possibility of energy release, and these semi-conductor properties are enhanced and vitally related to water. However, none of this research validates the idea that the excited electrons and potential release of energy can split the water and generating free electrons for biological use.

This leads us to a wonderful paper written by Arturo Solis, Marie Lara, and Luis Rendron titled Photoelectrochemical Properties of Melanin (Solis, Lara, and Rendon 2007). This paper proposed that melanin contains photoelectrochemical properties like chlorophyll in plants. This concept presented itself through an experiment involving human retinal tissue when studying the causes of blindness, and they found that oxygen levels increased 34% in ocular fluid when melanin was present, and they argue this wasn’t a result of ATP metabolism. Then the question becomes: where does this oxygen come from? To help answer this question, the researchers developed a prototype electrochemical cell using a 1.3% melanin solution with copper and aluminum electrodes. When this cell was exposed to continuous light, there was a stable production of electricity that lasted 10,000 hours. The conclusion of this paper was that the melanin absorbed the photons and used the energy to split the water molecule. The chemical reaction would potentially look something like this:

2H₂O + photons → O₂ + 4H⁺ + 4e⁻

In conclusion, the research explored above highly suggests that melanin is a protein that can split water to produce 4 electrons. These electrons can then be used by our mitochondria for cellular respiration.   References

Double, Kay L., Manfred Gerlach, Volker Schünemann, Alfred X. Trautwein, Luigi Zecca, Mario Gallorini, Moussa B. H. Youdim, Peter Riederer, and Dorit Ben-Shachar. 2003. “Iron-Binding Characteristics of Neuromelanin of the Human Substantia Nigra.” Biochemical Pharmacology 66 (3): 489–94.

Forest, S. E., and J. D. Simon. 1998. “Wavelength-Dependent Photoacoustic Calorimetry Study of Melanin.” Photochemistry and Photobiology 68 (3): 296–98.

McGinness, J., P. Corry, and P. Proctor. 1974. “Amorphous Semiconductor Switching in Melanins.” Science (New York, N.Y.) 183 (4127): 853–55.

Mostert, Albertus B., Benjamin J. Powell, Francis L. Pratt, Graeme R. Hanson, Tadeusz Sarna, Ian R. Gentle, and Paul Meredith. 2012. “Role of Semiconductivity and Ion Transport in the Electrical Conduction of Melanin.” Proceedings of the National Academy of Sciences of the United States of America 109 (23): 8943–47.

Sarna, T., W. Froncisz, and J. S. Hyde. 1980. “Cu2+ Probe of Metal-Ion Binding Sites in Melanin Using Electron Paramagentic Resonance Spectroscopy. II. Natural Melanin.” Archives of Biochemistry and Biophysics 202 (1): 304–13.

Solis, Arturo, Maria Lara, and Luis Rendon. 2007. “Photoelectrochemical Properties of Melanin.” Nature Precedings, November, 1–1.

Szpoganicz, Bruno, Shirley Gidanian, Philip Kong, and Patrick Farmer. 2002. “Metal Binding by Melanins: Studies of Colloidal Dihydroxyindole-Melanin, and Its Complexation by Cu(II) and Zn(II) Ions.” Journal of Inorganic Biochemistry 89 (1–2): 45–53.

Xu, Ri, Francesca Soavi, and Clara Santato. 2019. “An Electrochemical Study on the Effect of Metal Chelation and Reactive Oxygen Species on a Synthetic Neuromelanin Model.” Frontiers in Bioengineering and Biotechnology 7 (October): 227.