Short Peptide Binding in S100 A5 and A6: A Paradigm for the Biomolecular Evolution of Specificity
| dc.contributor.author | Wong, Caitlyn Emma | |
| dc.date.accessioned | 2018-12-15T17:22:59Z | |
| dc.date.available | 2018-12-15T17:22:59Z | |
| dc.date.issued | 2017-12 | |
| dc.description | 47 pages. Presented to the Department of Chemistry and Biochemistry and the Robert D. Clark Honors College in partial fulfillment of the requirements for the degree of Bachelor of Science December 2017 | |
| dc.description.abstract | S100A5 and S100A6 provide an excellent model for study of the evolution of binding specificity in proteins because they are structurally similar yet functionally diverse. We set out to determine the biochemical attributes and biological constraints responsible for the divergence of specificity between these paralogs that occurred post gene duplication of the S100A5/A6 ancestor. We first characterized the evolution of protein structure in this subfamily by sampling extant amniote orthologs, S100A5 and A6 ancestors, and the shared S100A5/A6 ancestor. We used circular dichroism (CD) spectroscopy to show a phylogenetic pattern of secondary structure and conformation change upon Ca2+ binding. The increase in response to Ca2+ binding in S100A5 orthologs and their shared ancestor is a derived trait relative to S100A6 and ancestral S100A5/A6. We looked to crystallography to identify the molecular mechanism for peptide binding in S100A5 and reveal the chemical basis for this observed divergence. We report crystallization conditions for human S100A5 in both the Ca2+-bound and Ca2+ and peptide-bound states that require further optimization before submission for diffraction. We then developed a co-immunoprecipitation protocol to isolate and identify targets of mouse S100A5 from olfactory bulb tissue. We report a maximal elution fraction of 0.54 for mouse S100A5 using our primary antibody and, despite cross-reactivity with mouse S100A6, an expectation of 60% of binding partners isolated to be of mouse S100A5. Our protocol provides a starting point for identifying targets bound by S100A5 in olfactory tissue. | en_US |
| dc.identifier.uri | https://hdl.handle.net/1794/24145 | |
| dc.language.iso | en_US | |
| dc.publisher | University of Oregon | |
| dc.rights | Creative Commons BY-NC-ND 4.0-US | |
| dc.subject | Biochemistry | en_US |
| dc.subject | Evolution | en_US |
| dc.subject | Binding specificity | en_US |
| dc.subject | Biophysics | en_US |
| dc.subject | Crystallography | en_US |
| dc.subject | Co-immunopreciptation | en_US |
| dc.subject | Olfactory Bulb | en_US |
| dc.title | Short Peptide Binding in S100 A5 and A6: A Paradigm for the Biomolecular Evolution of Specificity | |
| dc.type | Thesis/Dissertation |
Files
Original bundle
1 - 1 of 1