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Dr. John D. Simon Department
of Chemistry Duke
University |
“Probing
the Chemistry of Human Pigments”
Abstract
Human pigments play an important role in controlling
oxidative stress in human tissue. Melanin, a generic term to describe the dark
pigments, mitigates such stress in the brain, eye, and skin. While all the
pigments are grouped under a common name, the chemical properties of neuro,
ocular, and skin melanin differ. It is reasonable to hypothesize the function
of melanins differ among pigmented tissues, and oxidative damage to these
pigments can induce tissue-dependent biological responses. To understand how
human melanins affect oxidative stress requires knowledge of the
electrochemical properties of the surface of the intact pigment deposit and/or
individual melanosomes. Adverse effects on neurological function or vision may
result from localized damage to the pigments, and therefore the most desired
information is spatially-dependent properties of these organelles. Specific
goals of this work include: to provide new insights into the etiology of neural
degeneration observed in pigmented regions of the human brain through
understanding of the chemical and spatially-dependent electrochemical
properties of neuromelanin; to provide new insights into the etiology of
macular degeneration by understanding
the relationship between melanosomal damage and increased aerobic reactivity of
ocular melanosomes in the retinal pigment epithelium (RPE); and determine the
role of lipofuscin in compromising RPE melanosomes as the human eye ages. This
talk will introduce the pigment field, report of chemical and structure studies
used to characterize the pigments, and then present the current results from an
array of physical techniques followed by a discussion of their implications.
Biographical
sketch
Professor Simon received his B.A. from Williams College in 1979 and his Ph.D. from the Department of Chemistry at Harvard University in 1983. After a postdoctoral fellowship with Professor M.A. El-Sayed at UCLA, he joined the Department of Chemistry and Biochemistry at UCSD in 1985. Simon has earned numerous fellowships and awards for his scientific work, including the Presidential Young Investigator Award, Alfred P. Sloan Fellowship, Camille and Henry Dreyfus Teacher Scholar Award, and the Fresenius Award. He is a fellow of the American Association for the Advancement of Science and the American Physical Society. He has authored more than 190 publications, three books, and has given more than 200 invited presentations on his research. His textbook on physical chemistry, coauthored with Don McQuarrie, has become the standard book for this junior level course in the United States and has been translated into several languages. He is currently the editor of Photochemistry and Photobiology.
Simon came to the Department of Chemistry at Duke University as the George B. Geller Professor in 1998. He chaired the Department of Chemistry at Duke from 1999 to 2004 and assumed his current position as Vice-Provost for Academic Affairs in January 2005. As Vice-Provost, he is responsible for the administrative oversight of Duke's strategic planning process, the oversight of research centers in the areas of basic science and engineering, and promoting research and teaching across traditional scientific boundaries.