Biophysical Society Thematic Meeting

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

13-POS

Board 13

Synthesis of CCR6 Sulfopeptides to Probe Specific Contacts with the Chemokine CCL20

Marlon Dias

, Fabio C. Almeida

, Ana Paula Valente

, Viviane S. De Paula

Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.

Universidade Federal do Rio de

Janeiro-Polo Xerém, Rio de Janeiro, Brazil,

Chemokines are small soluble proteins that stimulate chemotactic cell migration through

interactions with chemokine receptors, a family of G protein-coupled receptors expressed in

leukocyte cell membranes. In addition to their inherent pro-inflammatory activity, chemokines

also contributes to many pathologies including auto-immune diseases and cancer. The N-

terminus domains of the chemokine receptors contain tyrosine amino acid residues. Tyrosine

sulfation is a post translational modification that enhances protein-protein interactions and the

sulfation in the N-terminus regions of the chemokine receptors enhance the binding affinity of

chemokine ligands and can modify the selectivity of a receptor. The aim of this work is

characterize the interactions of the chemokine CCL20 with several CCR6-derived extracellular

peptides by NMR spectroscopy. In this work we showed a strategy for synthesis of peptides

containing sulfotyrosine at one or more specific positions to explore the role of tyrosine sulfation

in recognition of the CCL20 by its receptor CCR6. We report the synthesis, purification and

analyses of peptides corresponding to residues 16-30 of CCR6 in sulfated and non-sulfated form

at the Y18, Y26 and Y27 positions. The non-sulfated peptide and sulfopeptide (sY27) were

obtained with success and with high yield. The samples exhibited a major peak on preparative

HPLC chromatograms and the correct masses of both peptides were verified by electrospray

ionization mass spectrometry. The peptide resonances were assigned by analysis of TOCSY

spectra. Next, we will demonstrate that sulfation of this peptide at one or both positions would

substantially enhance the affinity of chemokine binding. Our objective is understand which

sulfotyrosine present in the CCR6 sulfopeptide is critical for CCL20 recognition and highlights

the potential influence of initial binding interactions on receptor activation.