Event Title

Reactions of Singlet Oxygen with Free Amino Acids

Location

CSU Ballroom

Start Date

16-4-2013 10:00 AM

End Date

16-4-2013 12:00 PM

Student's Major

Chemistry and Geology

Student's College

Science, Engineering and Technology

Mentor's Name

John Thoemke

Mentor's Department

Chemistry and Geology

Mentor's College

Science, Engineering and Technology

Description

Molecular singlet oxygen is important to many biological processes including cell death. Some of these processes are caused by changes in protein structure and function that can be induced by reaction with singlet oxygen. To study aspects of this process, reactions between singlet oxygen and amino acids are being examined. Under visible light irradiation, Rose Bengal (RB) is used as the source of singlet oxygen and furfuryl alcohol (FFA) is used as a molecular probe to measure singlet oxygen concentration. First, a solution is made of RB and FFA. It is then exposed to visible light to initiate the production of singlet oxygen. From this solution, samples are taken at various times to measure the concentration of FFA using high performance liquid chromatography. As irradiation proceeds, the concentration of FFA diminishes due to the reaction with singlet oxygen. When added to the irradiated solution, an amino acid that reacts with singlet oxygen will compete with FFA, and the rate of FFA consumption will be slower. This was found to be true when histidine was added to the solution. Histidine was predicted to be reactive with singlet oxygen; the elevated concentration of FFA remaining in solution supports this prediction. Through analysis of the reaction kinetics, rate constants for the reactions between amino acids and singlet oxygen were determined. In future studies, reactions between singlet oxygen and specific proteins will be examined to determine if differences in protein structure affect reactivity.

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Apr 16th, 10:00 AM Apr 16th, 12:00 PM

Reactions of Singlet Oxygen with Free Amino Acids

CSU Ballroom

Molecular singlet oxygen is important to many biological processes including cell death. Some of these processes are caused by changes in protein structure and function that can be induced by reaction with singlet oxygen. To study aspects of this process, reactions between singlet oxygen and amino acids are being examined. Under visible light irradiation, Rose Bengal (RB) is used as the source of singlet oxygen and furfuryl alcohol (FFA) is used as a molecular probe to measure singlet oxygen concentration. First, a solution is made of RB and FFA. It is then exposed to visible light to initiate the production of singlet oxygen. From this solution, samples are taken at various times to measure the concentration of FFA using high performance liquid chromatography. As irradiation proceeds, the concentration of FFA diminishes due to the reaction with singlet oxygen. When added to the irradiated solution, an amino acid that reacts with singlet oxygen will compete with FFA, and the rate of FFA consumption will be slower. This was found to be true when histidine was added to the solution. Histidine was predicted to be reactive with singlet oxygen; the elevated concentration of FFA remaining in solution supports this prediction. Through analysis of the reaction kinetics, rate constants for the reactions between amino acids and singlet oxygen were determined. In future studies, reactions between singlet oxygen and specific proteins will be examined to determine if differences in protein structure affect reactivity.

Recommended Citation

Hron, Danielle. "Reactions of Singlet Oxygen with Free Amino Acids." Undergraduate Research Symposium, Mankato, MN, April 16, 2013.
http://cornerstone.lib.mnsu.edu/urs/2013/poster-session-A/30