Authors: Norrell, Johannes; Vohra, Shikhar; Nordlund, T. M.

Affiliation: Dept. of Physics, Univ. of Alabama at Birmingham
Journal: American Physical Society, Annual March Meeting, March 20-24, 2000 Minneapolis, MN, abstract #F36.093
Publication Date: 03/2000
Origin: APS
Bibliographic Code: 2000APS..MARF36093N


Sunscreens are designed to prevent skin cancer by absorbing ultraviolet radiation from the sun before it gets to the DNA in skin cells. The purpose of this work is to determine whether or not octyl methoxycinnamate, an active ingredient in many sunscreens, will bind to DNA. If so, the sunscreen could transfer the energy it absorbed from the sun to the DNA and cause damage. To determine this, we prepared samples with varying concentrations of cinnamate added to herring sperm DNA, sonicating the mixture to disperse the hydrophobic sunscreen into solution. Absorption and fluorescence spectra of the mixtures showed (i) much more sunscreen was dispersed into solution when DNA was present, and (ii) the spectra of both DNA and sunscreen differed from those of the separate solutions. We conclude that the octyl methoxycinnamate can indeed bind to DNA in aqueous solution. Energy transfer experiments from DNA to sunscreen and from sunscreen to 2-aminopurine- (a fluorescent DNA base) labeled DNA will be presented