Chemokines are mammalian proteins that regulate the migration of leukocytes, a central feature of inflammatory responses. Chemokines exert their activity by activation of G protein-coupled receptors expressed on the target leukocytes. Ticks are hematophagous arachnids that live on mammalian hosts and can transmit many viral and bacterial infections between their hosts. As a strategy to suppress the inflammatory responses of their mammalian hosts and thereby prolong their feeding and residence times, ticks have evolved the ability to produce salivary proteins, known as evasins, that bind to host chemokines, blocking activation of chemokine receptors and preventing leukocyte migration. We have identified evasins from a variety of tick species. Here we describe the expression and characterization of ACA-01, an evasin found in the tick species Amblyomma cajanennense. ACA-01 was successfully expressed in E.coli inclusion bodies then refolded. Alternatively, addition of an N-terminal SUMO tag enabled expression of soluble ACA-01 in the E.coli expression system. Analysis of the purified protein supported the formation of the predicted four intramolecular disulfide bonds. Analytical size exclusion chromatography indicated that ACA-01 is dimeric. Binding data, obtained using a competitive fluorescence anisotropy assay, showed that ACA-01 expressed in E. coli binds to some chemokines with dissociation equilibrium constants (KD) in the range 10-70 nM. Ongoing experiments are focussed on identifying the critical residues of ACA-01 for recognition of specific chemokines. These studies will establish the ground work for developing the anti-inflammatory therapeutic potential of evasin proteins.