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Pharmacologic Induction of Epidermal Melanin and Protection Against Sunburn in a Humanized Mouse Model
Published on: September 7, 2013
Melanin biosynthesis by Frankia strain CeI5
Wenlin Yuan1, Stephen H Burleigh, Jeffrey O Dawson
1Department of Molecular Biology and Pharmacology, Washington University School of Medicine, St Louis, MO 63110, USA.
Physiologia Plantarum
|February 7, 2008
Summary
This study confirms Frankia strain CeI5 produces melanin, a pigment previously uncharacterized in this genus. The research identifies the Raper and Mason pathway as the biochemical route for this melanin biosynthesis.
Area of Science:
- Microbiology
- Biochemistry
- Mycology
Background:
- Many Frankia strains exhibit pigmentation, suggesting melanin production.
- Melanin biosynthesis in Frankia remains poorly understood and uncharacterized.
Purpose of the Study:
- To determine if Frankia strain CeI5 produces melanin.
- To elucidate the biochemical pathway responsible for pigment production in Frankia.
Main Methods:
- Culturing Frankia strain CeI5 in a defined medium with L-tyrosine.
- Characterizing the pigment's properties (solvent resistance, reaction to oxidants/reductants, FeCl3 precipitation).
- Spectroscopic analysis of the extracted pigment and investigation of cofactor/inhibitor effects.
Main Results:
- Frankia strain CeI5 produced a dark, melanin-like pigment in tissues and culture medium.
- The pigment exhibited characteristic melanin properties, including UV-visible light absorption spectra.
- Copper ions enhanced melanin production, while KCN and tropolone inhibited it, indicating tyrosinase involvement.
Conclusions:
- Frankia strain CeI5 synthesizes melanin.
- Melanin production in Frankia strain CeI5 follows the Raper and Mason pathway, involving tyrosinase.
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