Discipline: Chemistry and Chemical Sciences
Subcategory: Biochemistry (not Cell and Molecular Biology and Genetics)
Symone Jackson - Fisk University
Co-Author(s): Saffron Little, Matthew Zlibut, Rekha Pattanayek, and Steven Damo, Fisk University, TN
Receptors are transmembrane protein molecules that transmit information across the cell membrane initiating signal transduction. The molecular mechanisms of this process remain poorly understood. The receptor for advanced glycation end products (RAGE) is an inflammation receptor that is activated by a diverse array of ligands including S100 proteins, high mobility group protein B1, a-beta peptide, and certain glycoproteins. How a single receptor recognizes many different ligands represents a fundamental biophysical question. The extracellular region of RAGE is comprised of three domains, V, C1 and C2. Previous studies identified a small antagonist peptide (RAP) derived from S100P that can inhibit RAGE signaling in cell-based assays. We hypothesized that the mechanism of RAP-RAGE inhibition is due to a direct interaction between the peptide and the extracellular region of RAGE and aimed to characterize this interaction biophysically. Using differential scanning fluorimetry, we observed a shift in melting temperature of the VC1 domain of RAGE in the presence of RAP as compared to RAGE alone. This suggests that RAP binds directly to RAGE with high affinity. We conducted a bioinformatics analysis that shows the RAP peptide is moderately conserved within the S100 protein family which suggests this motif may be involved in a general mode of S100-binding to RAGE. Computational docking experiments indicate RAP interacts with both a hydrophobic and charged surface of the V domain of RAGE. A survey of existing S100-RAGE structural models shows the conserved region corresponding to the RAP sequence does not typically interact with RAGE. Moving forward, we are using alternative approaches to validate the RAP-RAGE interaction, including ITC, fluorescence, and structural studies.
Not SubmittedFunder Acknowledgement(s): This work is funded by NSF Awards HRD1547757 (CREST) , HRD14900969 (HBCU-UP), and 1623280 (HBCU-UP), and NIH MD010396.
Faculty Advisor: Steven Damo, sdamo@fisk.edu
Role: I performed the experiments, analyzed the data, and helped interpret the results.