Presentation Title

Inhibition of Oxidative DNA-Protein Crosslinking via Tryptamine

Faculty Mentor

Dr. Eric Stemp

Start Date

18-11-2017 2:15 PM

End Date

18-11-2017 3:15 PM

Location

BSC-Ursa Minor 11

Session

Poster 3

Type of Presentation

Poster

Subject Area

physical_mathematical_sciences

Abstract

Oxidative damage to DNA is important amongst humans because it can lead to aging and cancer, and oxidative damage occurs mostly at the site of the easily oxidized base, guanine. When guanine becomes a radical, it can lead to a DNA-protein crosslink. We wanted to determine if we could inhibit the formation of oxidative DNA damage by adding tryptophan based antioxidants. Specifically, the ability of tryptamine to inhibit the damage within DNA was examined, including a determination of the concentrations at which tryptamine functions best. Blue light from a HeCd laser was used to irradiate Ru(phen)2dppz2+ in the presence of an oxidative quencher, producing a Ru(III) species (+1.6 V) that can oxidize guanine (+1.3 V) to make a guanine radical, which can react to make a DNA-protein crosslink or a form of oxidized guanine. Assays used for detecting the DNA-Protein Crosslinking were Chloroform Extraction Assay and Gel Electrophoresis. In the absence of tryptamine, a large amount of DNA-Protein Crosslinking was observed in both experiments. In the presence of tryptamine, only a small amount of DNA-Protein Crosslinking was seen. To confirm that the tryptamine played a role in redox repair of DNA, we carried out transient-absorption measurements and observed a long-lived signal at 510 nm, consistent with the formation of an indole radical. The use of tryptophan based antioxidants inhibits DNA oxidative damage.

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Nov 18th, 2:15 PM Nov 18th, 3:15 PM

Inhibition of Oxidative DNA-Protein Crosslinking via Tryptamine

BSC-Ursa Minor 11

Oxidative damage to DNA is important amongst humans because it can lead to aging and cancer, and oxidative damage occurs mostly at the site of the easily oxidized base, guanine. When guanine becomes a radical, it can lead to a DNA-protein crosslink. We wanted to determine if we could inhibit the formation of oxidative DNA damage by adding tryptophan based antioxidants. Specifically, the ability of tryptamine to inhibit the damage within DNA was examined, including a determination of the concentrations at which tryptamine functions best. Blue light from a HeCd laser was used to irradiate Ru(phen)2dppz2+ in the presence of an oxidative quencher, producing a Ru(III) species (+1.6 V) that can oxidize guanine (+1.3 V) to make a guanine radical, which can react to make a DNA-protein crosslink or a form of oxidized guanine. Assays used for detecting the DNA-Protein Crosslinking were Chloroform Extraction Assay and Gel Electrophoresis. In the absence of tryptamine, a large amount of DNA-Protein Crosslinking was observed in both experiments. In the presence of tryptamine, only a small amount of DNA-Protein Crosslinking was seen. To confirm that the tryptamine played a role in redox repair of DNA, we carried out transient-absorption measurements and observed a long-lived signal at 510 nm, consistent with the formation of an indole radical. The use of tryptophan based antioxidants inhibits DNA oxidative damage.