Inflammation is a normal response to any injury or infection. However, sustained inflammation can cause numerous diseases. A hallmark of inflammation is leukocyte recruitment to the affected tissue, regulated by small secretory proteins called chemokines, which bind and activate chemokine receptors expressed on the leukocyte surface (1). As a strategy to suppress detection, and thereby prolong their feeding and residence time, “ticks”, hematophagous arachnids, produce chemokine-binding proteins called 'evasins', which bind to host chemokines and block chemokine receptor activation, preventing leukocyte migration. Several studies have shown that evasins are natural, selective chemokine-inhibitory proteins with excellent potential as therapeutics for inflammatory diseases (2,3). Using bioinformatics, we identified variants of previously characterised “class A” evasins with ten cysteine residues forming five-disulfide bonds. We expressed and purified EVA-ACA1001 using the E. coli expression system. Analysis of the purified protein confirmed the predicted five intramolecular disulfide bonds. Binding data, obtained using surface plasmon resonance (SPR), showed that EVA-ACA1001 binds to multiple CC chemokines with dissociation equilibrium constants (Kd) in the range (0.01-100 nM). Furthermore, a cAMP inhibition assay demonstrated the chemokine inhibitory function of EVA-ACA1001, with IC50 values of 1 nM to 100 nM. Truncation of the N- and C-terminus revealed that the core region confers the chemokine binding and selectivity of EVA-ACA1001, a distinct feature of C10 evasins. Moreover, several crystal structures of a C10 evasin in complex with chemokines showed extensive hydrogen bonding between the evasin and the CC motif of the chemokine, a common feature of class A evasins. However, in contrast to traditional class A evasins, the core region of C10 evasins includes a deep hydrophobic pocket that can accommodate the first amino residue from the N- loop of CC chemokines, making it a broad binder. Thus, this study elucidates the relationship between structure and function of novel C10 evasins and paves a pathway for the engineering of potent anti-inflammatory molecules.