Biophysical Society Thematic Meeting - October 25-30, 2015

Polymers and Self Assembly: From Biology to Nanomaterials Poster Session I

46-POS Board 46 Structural Characterization of the Chemokine CCL20 and its Interaction with the Receptor CCR6 Gabriela Valle 1 , Ana Paula Valente 2 , Viviane De Paula 1 . 1 Núcleo Multidisciplinar de Pesquisa em Biologia – UFRJ, Polo Xerém, Duque de Caxias, Rio de Janeiro, Brazil, 2 Instituto de Bioquímica Médica, CNRMN - UFRJ, Rio de Janeiro, Rio de Janeiro, Brazil. Chemokines constitute a family of small proteins that regulate the immune response by signaling leukocytes through interaction with their transmembrane G-protein coupled receptors. However, the inappropriate regulation of these proteins is associated with an extraordinary number of pathophysiological disorders. Thus, there is a significant interest in understanding how these receptors work to developing drugs to block its activity. The chemokine CCL20 is a natural ligand of CCR6. CCR6-CCL20 interactions have been shown to be involved in several autoimmune and inflammatory processes. CCR6 is expressed in colorectal cancer and has been shown that the binding of the chemokine CCL20 promotes proliferation and migration of tumor cells in vitro. The aim of this work is to investigate the interaction of CCL20 with a peptide derived from the extracellular domain of the receptor CCR6 by NMR spectroscopy. Here we report the expression, purification and NMR characterization of the recombinant CCL20 and the peptide comprising the first 35 amino acid residues of the CCR6 N-terminal domain (CCR6 1-35 ). Following several expression and solubility tests we select the BL21(DE3)plysS strain for the expression of the fusion protein SUMO-CCL20, which was expressed in soluble form in minimal medium isotopically labeled with 15 NH 4 Cl for NMR studies. CCL20 was purified by nickel- affinity and reversed-phase chromatography. The CCL20 backbone and side chains resonance assignments will be achieved through analysis of triple resonance experiments. At the same time, the recombinant CCR6 1-35 peptide was overexpressed in Rosetta(DE3) strain and it is being purified. Chemical shift mapping and backbone dynamics of the interaction with the CCR6 peptide will reveal the binding surface on CCL20. These data could offer new insights into the structure-function relation of the CCL20-CCR6 interaction and may be helpful for the design of novel anti-tumor drugs.

- 65 -