What does melanin do



 

Melanin in humans and animals

Melanins (Greek μέλας (mèlas) "black") are reddish, brown or black pigments (colorants), which are produced by the enzymatic oxidation of tyrosine (enzymatic tanning) and which cause the coloring of the skin, hair or eyes in humans. They are found in vertebrates and insects, as colorants in the ink of squid, and also in microorganisms and plants. In vertebrates, melanin is formed in the melanocytes of the skin and in the retina of the eye.

In humans, melanin occurs mainly in two variants: a brownish-blackish (eumelanin), which is derived from the amino acids tyrosine and L-dopa, and a lighter yellowish-reddish (pheomelanin) variant, which contains sulfur. There are also different colored variants, so-called allomelanins, which are made from hydroxybenzenes. These are mainly found in plants, fungi and bacteria. Melanins almost always appear as mixed types and are also linked to lipids or protein.

The melanin in human skin and hair are mixed forms of eumelanins and the sulfur-containing phaeomelanins. The mixing ratio of these two types of melanin is one of the determining factors for a person's skin type. The phaeomelanin content in deep red hair is particularly high and decreases over brown and black hair. Melanin is increasingly formed in the skin when exposed to sunlight and is believed to be used to protect against the harmful effects of UV radiation from the sun. One of the main arguments for the UV protective function is the observation that heavily pigmented population groups suffer less from sun-induced skin cancer (“melanoma”) than less pigmented population groups. However, the high incidence of melanoma in red-haired people has long been known, so that this type of melanin may sensitize the skin rather than protect it. [1]

The synthesis of melanin can be disturbed by genetic predisposition or by damage to the genetic material acquired over time. If the production is blocked, the colorants in the skin, hair and eyes are also missing, resulting in a very light white skin, an unusually light hair color and blue, blue-gray or gray eyes, which depending on the angle of incidence of the light into them red appear (→ reason), surrender. One speaks of albinism and describes the affected organisms as albinos. In the event of overproduction, more and more dark spots appear in the skin (moles ("birthmarks"), freckles), which can become malignant (malignant melanoma ("melanoma")).

Melanin in mushrooms

 

On May 23, 2007 was a scientific paper [2][3][4] published under the direction of Arturo Casadevall, which deals with mushrooms that probably use melanin to convert radioactive radiation into energy that can be used by their organism (radiotrophic fungi).

It is expressly emphasized that the role of melanin in energy production is still unclear. The only thing that is clear is that the fungi obtained from samples from the sealed Chernobyl nuclear reactor:

  • a higher metabolic rate was given when they were fortified with melanin than with untreated mushrooms.
  • Changes in the electron configuration of the electron shell of their melanin were detected during the generation of energy. This indicates a changed energy level, which is also to be expected when generating energy.
  • a four-fold increase in NADH reduction can be observed when they are irradiated with radioactive substances. This is a metabolic process.
  • The metabolism of Wangiella dermatitidis and Cryptococcus neoformans was significantly more active than under normal conditions with a radiation exposure of around five hundred times the natural radiation exposure.

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  1. Medical University of Vienna - AKH consilium: Skin cancer (malignant melanoma)
  2. http://www.plosone.org/article/fetchArticle.action?articleURI=info:doi/10.1371/journal.pone.0000457
  3. http://www.plosone.org/static/license.action;jsessionid=20CA1AD861B408BCE91BB206E835B2F2
  4. http://creativecommons.org/licenses/by/2.5/

Category: pigment