A rapid and efficient way to obtain modified chemokines for functional and biophysical studies

Chemokines and their receptors control cell migration associated with routine immune surveillance, inflammation and development. They are also implicated in a large number of inflammatory diseases, cancer and HIV. Here we describe a rapid and efficient way to express and purify milligram quantities of multiple chemokine ligands (CCL7/MCP-3, CCL14/HCC-1, CCL3/MIP-1α and CXCL8/IL-8) containing C-terminal modifications to enable coupling to fluorescent dyes or small molecules such as biotin, in vitro. These labeled chemokines display wild-type behavior in both receptor binding and calcium mobilization assays. The ability to rapidly and inexpensively produce labeled chemokines opens the way for their use in many applications, including non-traditional chemokine-receptor interaction studies, both on intact cells and with purified receptor reconstituted in artificial membranes in vitro. Furthermore, the ability to immobilize chemokines to obtain ligand affinity columns aids in efforts to purify chemokine receptors for structural and biophysical studies, by facilitating the separation of functional proteins from their non-functional counterparts.