Figure 4.

Proposed binding mode of 43 in hCCR2b. (a) Overlay of 43 with the CCR2 intracellular ligand CCR2-RA-[R], showing that 43 interacts in a similar manner as CCR2-RA-[R]. (b) Docking of 43, displaying the interactions with CCR2. The amino group in R² makes an extra hydrogen-bond interaction with E^8×48, while the bromine group in R¹ makes an extra halogen bond with the backbone of V^1×53, which might contribute to the improved affinity of 43 to this receptor. Model of hCCR2 is based on the crystal structure of CCR2 (PDB code 5T1A),¹⁵ and amino acid residues are labeled according to their structure-based Ballesteros–Weinstein numbers.²⁵