DNA Selectivity of AT Hook Peptides
School Name
Governor's School for Science and Mathematics
Grade Level
12th Grade
Presentation Topic
Biochemistry
Presentation Type
Mentored
Oral Presentation Award
2nd Place
Written Paper Award
1st Place
Abstract
Certain proteins bind to DNA that contain specific sequences. HMGA proteins use AT hook motifs to bind to adenine and thymine rich DNA. During embryonic development, the binding between these proteins and DNA is present and normal. However, if these proteins bind to DNA during adulthood, the process can result in metastatic cancer. The purpose of this project is to gain a greater understanding of peptides that mimic the AT hook motif and their preference for different DNA sequences. This project tests the binding of a few peptides with many different DNA sequences. To do so, peptide is titrated into DNA and the fluorescence, which is affected by binding, is measured. The fluorescent emission value at 517 nm is measured as a function of peptide concentration and the data are then fit using the Michaelis-Menten equation, giving the average K value for each experiment. This value is the binding constant for the binding of each DNA by the peptide, and it represents how readily the peptide binds to that particular DNA. If the value is a low number, then the peptide binds to the sequence more tightly, but if the value is higher, it binds with more difficulty. The purpose of this experiment is to determine whether peptides with AT hooks show an affinity for specific DNA sequences over others. Results show that DNA sequences with “AT” in them tend to have lower binding constants and, therefore, are bound more easily by AT hook peptides than other sequences.
Recommended Citation
Tedrick, Madelaine, "DNA Selectivity of AT Hook Peptides" (2018). South Carolina Junior Academy of Science. 5.
https://scholarexchange.furman.edu/scjas/2018/all/5
Location
Neville 106
Start Date
4-14-2018 10:00 AM
Presentation Format
Oral and Written
DNA Selectivity of AT Hook Peptides
Neville 106
Certain proteins bind to DNA that contain specific sequences. HMGA proteins use AT hook motifs to bind to adenine and thymine rich DNA. During embryonic development, the binding between these proteins and DNA is present and normal. However, if these proteins bind to DNA during adulthood, the process can result in metastatic cancer. The purpose of this project is to gain a greater understanding of peptides that mimic the AT hook motif and their preference for different DNA sequences. This project tests the binding of a few peptides with many different DNA sequences. To do so, peptide is titrated into DNA and the fluorescence, which is affected by binding, is measured. The fluorescent emission value at 517 nm is measured as a function of peptide concentration and the data are then fit using the Michaelis-Menten equation, giving the average K value for each experiment. This value is the binding constant for the binding of each DNA by the peptide, and it represents how readily the peptide binds to that particular DNA. If the value is a low number, then the peptide binds to the sequence more tightly, but if the value is higher, it binds with more difficulty. The purpose of this experiment is to determine whether peptides with AT hooks show an affinity for specific DNA sequences over others. Results show that DNA sequences with “AT” in them tend to have lower binding constants and, therefore, are bound more easily by AT hook peptides than other sequences.
